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Enzymes and Substrates
 
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a thingy about enzymes and stuff
Views: 19867 lucyshackell1
Enzymes
 
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048 - Enzymes Paul Andersen explains how enzymes are used to break down substrates. The correct shape of the active site allows a key/lock fit between the enzyme and the substrate. The enzyme catalase is used to break down hydrogen peroxide. The importance of cofactors and coenzymes is emphasized. Competitive and allosteric inhibition is also included. Intro Music Atribution Title: I4dsong_loop_main.wav Artist: CosmicD Link to sound: http://www.freesound.org/people/CosmicD/sounds/72556/ Creative Commons Atribution License
Views: 1229934 Bozeman Science
Enzymes | Biology for All | FuseSchool
 
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Enzymes are really important proteins, that speed up the rates of reactions such as in photosynthesis, respiration and protein synthesis. The enzymes and substrates are always moving, and occasionally they collide at the right speed and orientation so that the substrate fits into the enzyme at the active site. Collision theory dictates that collisions must occur with sufficient energy and in a specific orientation for a reaction to occur. Enzymes are specialised; their active site matches the shape of the specific substrate that they react with. The enzyme and the substrate fit together using a lock and key mechanism. Once the substrate is in the active site, the reaction takes place. The required product is produced and the enzyme releases itself and carries on moving around. The enzyme could be protease, which breaks down proteins into amino acids. Or carbohydrase which breaks down carbohydrates into glucose. Or lipase which breaks down fats into fatty acids and glycerols. Hydrogen peroxide is often formed as a result of reactions in cells, and if it is left to build up it is harmful. Luckily, we have catalase enzymes that are really fast. They break the hydrogen peroxide down into the harmless water and oxygen. Equally, enzymes can help build up molecules like this… but the process is still exactly the same. Whilst enzymes do fantastic things, they are sensitive. Each enzyme has optimum conditions under which it works best. Firstly, there needs to be enough substrate around - they need a high enough substrate concentration for the reaction that they catalyse. If there is too little substrate, then the rate of reaction is slowed. Sometimes, if there is too much product around then the reaction slows because the enzymes and substrates have less chance of bumping into each other. So the product needs to be removed for a higher rate of reaction. Enzymes also have optimum pH and temperature conditions. Up to a point, an increase in temperature causes increased rate of reaction because there is more heat energy. More energy means more collisions. However, above a certain temperature the rate drops off due to denaturing. We will look at the effect of pH and temperature on enzymes in our video ‘Denaturation of Enzymes’. The pH and temperature optimum conditions are specific to the conditions in which they work in; an enzyme that works in the stomach for example would have a more acidic optimum pH. And of course, there need to be enough enzymes around for the rate of reaction to be optimised. So we know that enzymes and substrates fit together at the active site and form a ‘lock and key’ mechanism. The enzyme then releases the product and can be reused again. They are sensitive to temperature and pH, and there needs to be sufficient enzyme and substrate concentrations for reactions to occur. Enzymes not only control all kinds of reactions such as in photosynthesis, respiration, digestion and protein synthesis, but we also make use of them in day to day life. Protease and lipase enzymes are used in biological washing powders to remove proteins and fats from stains in our clothes. We also use enzymes in our food and drink industries; pectinase is used to break down the cells in fruit when making fruit juice so that more juice is released. SUBSCRIBE to the FuseSchool YouTube channel for many more educational videos. Our teachers and animators come together to make fun & easy-to-understand videos in Chemistry, Biology, Physics, Maths & ICT. VISIT us at www.fuseschool.org, where all of our videos are carefully organised into topics and specific orders, and to see what else we have on offer. Comment, like and share with other learners. You can both ask and answer questions, and teachers will get back to you. These videos can be used in a flipped classroom model or as a revision aid. Find all of our Chemistry videos here: https://www.youtube.com/watch?v=cRnpKjHpFyg&list=PLW0gavSzhMlReKGMVfUt6YuNQsO0bqSMV Find all of our Biology videos here: https://www.youtube.com/watch?v=tjkHzEVcyrE&list=PLW0gavSzhMlQYSpKryVcEr3ERup5SxHl0 Find all of our Maths videos here: https://www.youtube.com/watch?v=hJq_cdz_L00&list=PLW0gavSzhMlTyWKCgW1616v3fIywogoZQ Twitter: https://twitter.com/fuseSchool Access a deeper Learning Experience in the FuseSchool platform and app: www.fuseschool.org Follow us: http://www.youtube.com/fuseschool Friend us: http://www.facebook.com/fuseschool This Open Educational Resource is free of charge, under a Creative Commons License: Attribution-NonCommercial CC BY-NC ( View License Deed: http://creativecommons.org/licenses/by-nc/4.0/ ). You are allowed to download the video for nonprofit, educational use. If you would like to modify the video, please contact us: [email protected]
Function of Enzymes: Substrate, Active Site & Activation Energy
 
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Visit Study.com for thousands more videos like this one. You'll get full access to our interactive quizzes and transcripts and can find out how to use our videos to earn real college credit. YouTube hosts only the first few lessons in each course. The rest are at Study.com. Take the next step in your educational future and graduate with less debt and in less time.
Views: 115817 Study.com
Enzymes (Updated)
 
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The Amoeba Sisters explain enzymes and how they interact with their substrates. Vocabulary covered includes active site, induced fit, coenzyme, and cofactor. Also the importance of ideal pH and temperatures for enzymes are discussed. This video has a handout here: http://www.amoebasisters.com/handouts.html Support us on Patreon! http://www.patreon.com/amoebasisters Our FREE resources: GIFs: http://www.amoebasisters.com/gifs.html Handouts: http://www.amoebasisters.com/handouts.html Comics: http://www.amoebasisters.com/parameciumparlorcomics Connect with us! Website: http://www.AmoebaSisters.com Twitter: http://www.twitter.com/AmoebaSisters Facebook: http://www.facebook.com/AmoebaSisters Tumblr: http://www.amoebasisters.tumblr.com Pinterest: http://www.pinterest.com/AmoebaSister­s Instagram: https://www.instagram.com/amoebasistersofficial/ Visit our Redbubble store at http://www.amoebasisters.com/store.html The Amoeba Sisters videos demystify science with humor and relevance. The videos center on Pinky's certification and experience in teaching science at the high school level. Pinky's teacher certification is in grades 4-8 science and 8-12 composite science (encompassing biology, chemistry, and physics). Amoeba Sisters videos only cover concepts that Pinky is certified to teach, and they focus on her specialty: secondary life science. For more information about The Amoeba Sisters, visit: http://www.amoebasisters.com/about-us.html We cover the basics in biology concepts at the secondary level. If you are looking to discover more about biology and go into depth beyond these basics, our recommended reference is the FREE, peer reviewed, open source OpenStax biology textbook: https://openstax.org/details/books/biology We take pride in our AWESOME community, and we welcome feedback and discussion. However, please remember that this is an education channel. See YouTube's community guidelines https://www.youtube.com/yt/policyandsafety/communityguidelines.html and YouTube's policy center https://support.google.com/youtube/topic/2676378?hl=en&ref_topic=6151248. We also reserve the right to remove comments with vulgar language. Music is this video is listed free to use/no attribution required from the YouTube audio library https://www.youtube.com/audiolibrary/music?feature=blog We have YouTube's community contributed subtitles feature on to allow translations for different languages. YouTube automatically credits the different language contributors below (unless the contributor had opted out of being credited). We are thankful for those that contribute different languages. If you have a concern about community contributed contributions, please contact us.
Views: 985160 Amoeba Sisters
Enzyme substrate complex
 
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This enzymology video is about the enzyme substrate complex. http://shomusbiology.com/ Download the study materials here- http://shomusbiology.com/bio-materials.html Remember Shomu’s Biology is created to spread the knowledge of life science and biology by sharing all this free biology lectures video and animation presented by Suman Bhattacharjee in YouTube. All these tutorials are brought to you for free. Please subscribe to our channel so that we can grow together. You can check for any of the following services from Shomu’s Biology- Buy Shomu’s Biology lecture DVD set- www.shomusbiology.com/dvd-store Shomu’s Biology assignment services – www.shomusbiology.com/assignment -help Join Online coaching for CSIR NET exam – www.shomusbiology.com/net-coaching We are social. Find us on different sites here- Our Website – www.shomusbiology.com Facebook page- https://www.facebook.com/ShomusBiology/ Twitter - https://twitter.com/shomusbiology SlideShare- www.slideshare.net/shomusbiology Google plus- https://plus.google.com/113648584982732129198 LinkedIn - https://www.linkedin.com/in/suman-bhattacharjee-2a051661 Youtube- https://www.youtube.com/user/TheFunsuman Thank you for watching This video explains three important mechanisms by which an enzyme catalyses reactions. In biochemistry, a substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate(s). In the case of a single substrate, the substrate bonds with the enzyme active site, and an enzyme-substrate complex is formed. The substrate is transformed into one or more products, which are then released from the active site. The active site is now free to accept another substrate molecule. In the case of more than one substrate, these may bind in a particular order to the active site, before reacting together to produce products. A substrate is called 'chromogenic', if it gives rise to a colored product when acted on by an enzyme. For example, curd formation (rennet coagulation) is a reaction that occurs upon adding the enzyme rennin to milk. In this reaction, the substrate is a milk protein (e.g., casein) and the enzyme is rennin. The products are two polypeptides that have been formed by the cleavage of the larger peptide substrate. Another example is the chemical decomposition of hydrogen peroxide carried out by the enzyme catalase. As enzymes are catalysts, they are not changed by the reactions they carry out. The substrate(s), however, is/are converted to product(s). Here, hydrogen peroxide is converted to water and oxygen gas. E + S ⇌ ES → EP ⇌ E + P where E = enzyme, S = substrate(s), P = product(s). While the first (binding) and third (unbinding) steps are, in general, reversible, the middle step may be irreversible (as in the rennin and catalase reactions just mentioned) or reversible (e.g., many reactions in the glycolysis metabolic pathway). By increasing the substrate concentration, the rate of reaction will increase due to the likelihood that the number of enzyme-substrate complexes will increase; this occurs until the enzyme concentration becomes the limiting factor. It is important to note that the substrates that a given amino acid in vitro may not necessarily reflect the physiological, endogenous substrates of the enzyme in vivo. That is to say that enzymes do not necessarily perform all the reactions in the body that may be possible in the laboratory. For example, while fatty acid amide hydrolase (FAAH) can hydrolyze the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide at comparable rates in vitro, genetic or pharmacological disruption of FAAH elevates anandamide but not 2-AG, suggesting that 2-AG is not an endogenous, in vivo substrate for FAAH.[1] In another example, the N-acyl taurines (NATs) are observed to increase dramatically in FAAH-disrupted animals, but are actually poor in vitro FAAH substrates.[2] Source of the article published in description is Wikipedia. I am sharing their material. © by original content developers of Wikipedia. Link- http://en.wikipedia.org/wiki/Main_Page
Views: 12832 Shomu's Biology
Enzyme kinetics vmax and km
 
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Enzyme kinetics biochemistry vmax and Km lecture - This lecture explains about the enzyme kinetics of the enzyme reaction that includes explanation of vmax and Km. Maximum velocity of the enzyme substrate reaction and enzyme affinity towards a reaction is also explained with this video lecture. For more information, log on to- http://www.shomusbiology.com/ Get Shomu's Biology DVD set here- http://www.shomusbiology.com/dvd-store/ Download the study materials here- http://shomusbiology.com/bio-materials.html Remember Shomu’s Biology is created to spread the knowledge of life science and biology by sharing all this free biology lectures video and animation presented by Suman Bhattacharjee in YouTube. All these tutorials are brought to you for free. Please subscribe to our channel so that we can grow together. You can check for any of the following services from Shomu’s Biology- Buy Shomu’s Biology lecture DVD set- www.shomusbiology.com/dvd-store Shomu’s Biology assignment services – www.shomusbiology.com/assignment -help Join Online coaching for CSIR NET exam – www.shomusbiology.com/net-coaching We are social. Find us on different sites here- Our Website – www.shomusbiology.com Facebook page- https://www.facebook.com/ShomusBiology/ Twitter - https://twitter.com/shomusbiology SlideShare- www.slideshare.net/shomusbiology Google plus- https://plus.google.com/113648584982732129198 LinkedIn - https://www.linkedin.com/in/suman-bhattacharjee-2a051661 Youtube- https://www.youtube.com/user/TheFunsuman Thank you for watching the biochemistry lecture on enzyme kinetics reaction.
Views: 79240 Shomu's Biology
Enzyme catalysis
 
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For more information, log on to- http://shomusbiology.weebly.com/ Download the study materials here- http://shomusbiology.weebly.com/bio-materials.html Enzyme catalysis is the catalysis of chemical reactions by specialized proteins known as enzymes. Catalysis of biochemical reactions in the cell is vital due to the very low reaction rates of the uncatalysed reactions.[citation needed] The mechanism of enzyme catalysis is similar in principle to other types of chemical catalysis. By providing an alternative reaction route the enzyme reduces the energy required to reach the highest energy transition state of the reaction. The reduction of activation energy (Ea) increases the number of reactant molecules with enough energy to reach the activation energy and form the product. The favored model for the enzyme-substrate interaction is the induced fit model.[1] This model proposes that the initial interaction between enzyme and substrate is relatively weak, but that these weak interactions rapidly induce conformational changes in the enzyme that strengthen binding. The advantages of the induced fit mechanism arise due to the stabilizing effect of strong enzyme binding. There are two different mechanisms of substrate binding: uniform binding, which has strong substrate binding, and differential binding, which has strong transition state binding. The stabilizing effect of uniform binding increases both substrate and transition state binding affinity, while differential binding increases only transition state binding affinity. Both are used by enzymes and have been evolutionarily chosen to minimize the Ea of the reaction. Enzymes which are saturated, that is, have a high affinity substrate binding, require differential binding to reduce the Ea, whereas small substrate unbound enzymes may use either differential or uniform binding. These effects have led to most proteins using the differential binding mechanism to reduce the Ea, so most proteins have high affinity of the enzyme to the transition state. Differential binding is carried out by the induced fit mechanism - the substrate first binds weakly, then the enzyme changes conformation increasing the affinity to the transition state and stabilizing it, so reducing the activation energy to reach it. It is important to clarify, however, that the induced fit concept cannot be used to rationalize catalysis. That is, the chemical catalysis is defined as the reduction of Ea‡ (when the system is already in the ES‡) relative to Ea‡ in the uncatalyzed reaction in water (without the enzyme). The induced fit only suggests that the barrier is lower in the closed form of the enzyme but does not tell us what the reason for the barrier reduction is. Induced fit may be beneficial to the fidelity of molecular recognition in the presence of competition and noise via the conformational proofreading Source of the article published in description is Wikipedia. I am sharing their material. Copyright by original content developers of Wikipedia. Link- http://en.wikipedia.org/wiki/Main_Page PPT source- National Taiwan University, Jaung Web. Copywright by original content developer. Link- http://juang.bst.ntu.edu.tw/BCbasics/Animation.htm
Views: 23178 Shomu's Biology
3.6.3 Explain factors affecting enzyme activity
 
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Temperature: As temperature increases so to does the kinetic energy of the enzyme and substrate molecules which randomly collide. The frequency of collisions increases as the temperature increases thus initially increasing the rate of reaction. This occurs up to a maximum rate of reaction and the temperature at which the maximum rate of reaction is reached is referred to as the optimum temperature. Beyond the optimum temperature, increasing temperature increases the kinetic energy of the molecules to the point that the three-dimensional shape of the enzyme can be lost. Thus the shape of its active site changes and can no longer bind to the substrate, reducing the rate of reaction beyond the optimum temperature. pH: All enzymes have an optimum pH at which they have their maximum rate of reaction. Increasing pH values are as a result of the addition of hydroxide ions (OH-) while decreasing pH values are as a result of the addition of hydrogen ions (H+). The addition of either OH- or H+ can change the charges of the amino acids that make up the polypeptide chains of the enzyme. This can alter the bonding in the protein and change the shape of the active site resulting in denaturation, or alternatively it can prevent the substrate from binding with the enzyme's active site. Therefore either increasing or decreasing pH from the optimum value results in decreasing rate of enzyme activity. Substrate concentration: When discussing substrate concentration it is assumed that enzyme concentration remains constant. When substrate concentration is increased the rate of enzyme activity increases as the enzyme's active sites are gradually filled through the increased number of collisions with the substrate (due to increased substrate concentration). However, there comes a point when all of the enzyme's active sites are bound with substrates and the enzyme's are working at their maximum rate of reaction. Any increase in substrate concentration beyond this point will not result in any additional increase in rate of enzyme activity.
Views: 137482 Stephanie Castle
Enzymatic Reactions: Types of Reactions & Enzymes – Biochemistry | Lecturio
 
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This video “Enzymatic Reactions: Types of Reactions & Enzymes” is part of the Lecturio course “Biochemistry” ► WATCH the complete course on http://lectur.io/emzymaticreactions ► LEARN ABOUT: - Types of Enzymatic reactions - Single substrate – Single product - Single substrate – Multiple products - Multiple substrates – Single products - Multiple substrates – Multiple products - How enzymes bind substrates - Their ability to catalyzed reactions - Chemical catalyst - How substrates affect enzymes on binding - The interaction of the enzymes - ES complex (Enzyme substrate complex) - Changes of shape of the enzyme - ES* complex - Transfer of one substrate to another - EP complex (Enzyme product complex) - The steps of catalysis ► THE PROF: Your lecturer is Professor Kevin Ahern. He is currently teaching biochemistry and biophysics at the Oregon State University, where he has also successfully completed his Ph.D. in biochemistry. Beside writing poetry and songs about several topics including medical ones—believe it or not as well—he has written the popular ebooks “Biochemistry Free and Easy” and "Kevin and Indira's Guide to Getting Into Medical School." His edutaining videos on YouTube were watched over 2.75 million times making him a medical education YouTube star. ► LECTURIO is your single-point resource for medical school: Study for your classes, USMLE Step 1, USMLE Step 2, MCAT or MBBS with video lectures by world-class professors, recall & USMLE-style questions and textbook articles. Create your free account now: http://lectur.io/emzymaticreactions ► INSTALL our free Lecturio app iTunes Store: https://app.adjust.com/z21zrf Play Store: https://app.adjust.com/b01fak ► READ TEXTBOOK ARTICLES related to this video: Enzymes – Biocatalysts of Metabolism http://lectur.io/enzymaticreactionsarticle ► SUBSCRIBE to our YouTube channel: http://lectur.io/subscribe ► WATCH MORE ON YOUTUBE: http://lectur.io/playlists ► LET’S CONNECT: • Facebook: https://www.facebook.com/lecturio.medical.education.videos • Instagram: https://www.instagram.com/lecturio_medical_videos • Twitter: https://twitter.com/LecturioMed
Substrates and Products in Chemical Reactions
 
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Synthetic Biology One is a free, open online course in synthetic biology beginning at the undergraduate level. We welcome scientists, artists, journalists, policymakers, or anyone interested in designing with DNA. Meet us at syntheticbiology1.com!
What are Enzymes, Substrate and Product? - BiochemDen.com
 
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Visit: https://www.biochemden.com/enzyme-basic-video-presentation/ Enzymes are macromolecular biological catalysts. Enzymes accelerate chemical reactions. The molecules upon which enzymes may act are called substrates and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called enzymology and a new field of pseudo-enzyme analysis has recently grown up, recognising that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudo catalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Most enzymes are proteins, although a few are catalytic RNA molecules. The latter are called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction rate by lowering its activation energy. Some enzymes can make their conversion of substrate to product occur many millions of times faster. An extreme example is orotidine 5'-phosphate decarboxylase, which allows a reaction that would otherwise take millions of years to occur in milliseconds. Chemically, enzymes are like any catalyst and are not consumed in chemical reactions, nor do they alter the equilibrium of a reaction. Enzymes differ from most other catalysts by being much more specific. Enzyme activity can be affected by other molecules: inhibitors are molecules that decrease enzyme activity, and activators are molecules that increase activity. Many therapeutic drugs and poisons are enzyme inhibitors. An enzyme's activity decreases markedly outside its optimal temperature and pH. Follow: Blog: https://www.biochemden.com Facebook: https://www.facebook.com/BiochemDen Twitter: https://twitter.com/biochemden Google Plus: https://plus.google.com/+BiochemdenIn Pinterest: https://www.pinterest.com/biochemden/ Telegram: https://t.me/biochemden #BiochemDen #Biochemistry #Metabolism #BiochemistryResources #Biochem #Biomolecules #biochemistry #Biochemden #Biochemistryeducation
Views: 43 Biochemistry Den
Enzyme kinetics animation
 
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This animation explains about the enzyme kinetics vmax km. http://shomusbiology.com/ Download the study materials here- http://shomusbiology.com/bio-materials.html Remember Shomu’s Biology is created to spread the knowledge of life science and biology by sharing all this free biology lectures video and animation presented by Suman Bhattacharjee in YouTube. All these tutorials are brought to you for free. Please subscribe to our channel so that we can grow together. You can check for any of the following services from Shomu’s Biology- Buy Shomu’s Biology lecture DVD set- www.shomusbiology.com/dvd-store Shomu’s Biology assignment services – www.shomusbiology.com/assignment -help Join Online coaching for CSIR NET exam – www.shomusbiology.com/net-coaching We are social. Find us on different sites here- Our Website – www.shomusbiology.com Facebook page- https://www.facebook.com/ShomusBiology/ Twitter - https://twitter.com/shomusbiology SlideShare- www.slideshare.net/shomusbiology Google plus- https://plus.google.com/113648584982732129198 LinkedIn - https://www.linkedin.com/in/suman-bhattacharjee-2a051661 Youtube- https://www.youtube.com/user/TheFunsuman Thank you for watching Enzyme kinetics is the study of the chemical reactions that are catalysed by enzymes. In enzyme kinetics, the reaction rate is measured and the effects of varying the conditions of the reaction is investigated. Studying an enzyme's kinetics in this way can reveal the catalytic mechanism of this enzyme, its role in metabolism, how it activity is controlled, and how a drug or an agonist might inhibit the enzyme. Enzymes are usually protein molecules that manipulate other molecules — the enzymes' substrates. These target molecules bind to an enzyme's active site and are transformed into products through a series of steps known as the enzymatic mechanism. These mechanisms can be divided into single-substrate and multiple-substrate mechanisms. Kinetic studies on enzymes that only bind one substrate, such as triosephosphate isomerase, aim to measure the affinity with which the enzyme binds this substrate and the turnover rate. Some other examples of enzymes are phosphofructokinase and hexokinase, both of which are important for cellular respiration (glycolysis). When enzymes bind multiple substrates, such as dihydrofolate reductase (shown right), enzyme kinetics can also show the sequence in which these substrates bind and the sequence in which products are released. An example of enzymes that bind a single substrate and release multiple products are proteases, which cleave one protein substrate into two polypeptide products. Others join two substrates together, such as DNA polymerase linking a nucleotide to DNA. Although these mechanisms are often a complex series of steps, there is typically one rate-determining step that determines the overall kinetics. This rate-determining step may be a chemical reaction or a conformational change of the enzyme or substrates, such as those involved in the release of product(s) from the enzyme. Source of the article published in description is Wikipedia. I am sharing their material. © by original content developers of Wikipedia. Link- http://en.wikipedia.org/wiki/Main_Page Animation source: Essential biochemistry, enzyme kinetics link- http://www.wiley.com/college/pratt/0471393878/instructor/animations/enzyme_kinetics/index.html
Views: 61783 Shomu's Biology
Induced fit model of enzyme catalysis | Chemical Processes | MCAT | Khan Academy
 
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Get a better appreciation for how enzymes and substrates bind together. By Ross Firestone. Created by Ross Firestone. Watch the next lesson: https://www.khanacademy.org/test-prep/mcat/chemical-processes/enzymes/v/the-six-types-of-enzymes?utm_source=YT&utm_medium=Desc&utm_campaign=mcat Missed the previous lesson? https://www.khanacademy.org/test-prep/mcat/chemical-processes/enzymes/v/an-introduction-to-enzymes-and-catalysis?utm_source=YT&utm_medium=Desc&utm_campaign=mcat MCAT on Khan Academy: Go ahead and practice some passage-based questions! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s MCAT channel: https://www.youtube.com/channel/UCDkK5wqSuwDlJ3_nl3rgdiQ?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 186761 khanacademymedicine
Enzymes and Catalysts
 
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This video will discuss the basics of chemical reactions and the functions of enzymes as a catalyst. Teachers: This PowerPoint can be purchased from my online store. The link below will provide the details. https://www.teacherspayteachers.com/Product/Enzymes-and-Catalysts-PowerPoint-free-student-handout-2677210 Key Words: Enzyme Catalyst Protein Amino acid Exothermic Exogonic Endothermic Endergonic Chemical reaction Organic Carbon Hydrolysis Dehydration synthesis Activation energy Active site Chemistry
Views: 83945 Beverly Biology
Induced Fit Model of Enzyme Action
 
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The induced fit model refers to the interaction between the enzyme and the substrate. The substrate binds to the active site of the enzyme due to a complementary shape. Once the substrate has bound the enzyme changes shape slightly to form an even more exact fit (induced fit). The enzyme then catalyses the reaction and releases the product(s) so that the process can occur again. For more Biology video lessons check out www.anytimeeducation.com
Views: 11647 Jeremy LeCornu
Enzyme inhibition
 
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For more information, log on to- http://shomusbiology.weebly.com/ Download the study materials here- http://shomusbiology.weebly.com/bio-materials.html An enzyme inhibitor is a molecule, which binds to enzymes and decreases their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. They are also used as herbicides and pesticides. Not all molecules that bind to enzymes are inhibitors; enzyme activators bind to enzymes and increase their enzymatic activity, while enzyme substrates bind and are converted to products in the normal catalytic cycle of the enzyme. The binding of an inhibitor can stop a substrate from entering the enzyme's active site and/or hinder the enzyme from catalyzing its reaction. Inhibitor binding is either reversible or irreversible. Irreversible inhibitors usually react with the enzyme and change it chemically (e.g. via covalent bond formation). These inhibitors modify key amino acid residues needed for enzymatic activity. In contrast, reversible inhibitors bind non-covalently and different types of inhibition are produced depending on whether these inhibitors bind to the enzyme, the enzyme-substrate complex, or both. Many drug molecules are enzyme inhibitors, so their discovery and improvement is an active area of research in biochemistry and pharmacology. A medicinal enzyme inhibitor is often judged by its specificity (its lack of binding to other proteins) and its potency (its dissociation constant, which indicates the concentration needed to inhibit the enzyme). A high specificity and potency ensure that a drug will have few side effects and thus low toxicity. Enzyme inhibitors also occur naturally and are involved in the regulation of metabolism. For example, enzymes in a metabolic pathway can be inhibited by downstream products. This type of negative feedback slows the production line when products begin to build up and is an important way to maintain homeostasis in a cell. Other cellular enzyme inhibitors are proteins that specifically bind to and inhibit an enzyme target. This can help control enzymes that may be damaging to a cell, like proteases or nucleases. A well-characterised example of this is the ribonuclease inhibitor, which binds to ribonucleases in one of the tightest known protein--protein interactions.[1] Natural enzyme inhibitors can also be poisons and are used as defences against predators or as ways of killing prey. Source of the article published in description is Wikipedia. I am sharing their material. Copyright by original content developers of Wikipedia. Link- http://en.wikipedia.org/wiki/Main_Page PPT source- National Taiwan University, Jaung Web. Copywright by original content developer. Link- http://juang.bst.ntu.edu.tw/BCbasics/Animation.htm
Views: 36797 Shomu's Biology
√√ The effects of substrate concentration on enzymes | iitutor
 
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https://www.iitutor.com As mentioned in the experiment ‘The effects of pH on Enzymes’: This enzyme facilitates the decomposition of hydrogen peroxide (a toxic by-product of the body) into water and oxygen. The reaction of catalase in the decomposition of living tissue. We have already discovered the optimum pH level is pH7, this experiment looks at varying concentrations of the substrate, and its effect on the rate of activity. Hypothesis: When hydrogen peroxide is added in various concentrations, the enzyme reaction rate will increase with increasing substrate concentration. 1. Place catalase paper 30mL of Hydrogen peroxide 0.3% solution. 2. Using a stopwatch, determine how long it takes for reaction to take place. 3. Repeat steps 1-2 with catalase in solutions of 30mL of Hydrogen peroxide 0.7%, Hydrogen peroxide 1.5% and Hydrogen peroxide 3.0%. 4. Record results in a table and draw a graph of the results. Do your results support your hypothesis? How could you improve this experiment? Name any safety precautions you followed. Your results illustrate that with increasing substrate concentration, the reaction rate is faster. However beyond 1.5% of hydrogen peroxide, the enzyme is saturated (all active sites are taken) with substrate. This means at 3.0% hydrogen peroxide, the reaction does not increase, nor decrease, it plateaus. This means the reaction is working at its maximum rate, and will continue working at that rate until all substrates are broken down. The only way the reaction rate would increase, is if more enzyme was added to the solution. Therefore, the rate of reaction is in proportion to the substrate concentration.
Views: 5041 iitutor.com
Michaelis-Menten Kinetics: Considerations & Time Relation – Biochemistry | Lecturio
 
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This video “Michaelis-Menten Kinetics: Considerations & Time Relation” is part of the Lecturio course “Biochemistry” ► WATCH the complete course on http://lectur.io/michaelismenten ► LEARN ABOUT: - Michaelis-Menten Graph - Concentration of product (P) in proportion to time - Concentration of enzyme substrate (ES) in proportion to time - Concentration of enzyme (E) in proportion to time - Concentration of substrate (S) in proportion to time - Pre-steady state conditions - Steady state conditions - Conversion of enzymes substrate complex into product ► THE PROF: Your lecturer is Professor Kevin Ahern. He is currently teaching biochemistry and biophysics at the Oregon State University, where he has also successfully completed his Ph.D. in biochemistry. Beside writing poetry and songs about several topics including medical ones—believe it or not as well—he has written the popular ebooks “Biochemistry Free and Easy” and "Kevin and Indira's Guide to Getting Into Medical School." His edutaining videos on YouTube were watched over 2.75 million times making him a medical education YouTube star. ► LECTURIO is your single-point resource for medical school: Study for your classes, USMLE Step 1, USMLE Step 2, MCAT or MBBS with video lectures by world-class professors, recall & USMLE-style questions and textbook articles. Create your free account now: http://lectur.io/michaelismenten ► INSTALL our free Lecturio app iTunes Store: https://app.adjust.com/z21zrf Play Store: https://app.adjust.com/b01fak ► READ TEXTBOOK ARTICLES related to this video: Enzymes – Biocatalysts of Metabolism http://lectur.io/michaelismentenarticle ► SUBSCRIBE to our YouTube channel: http://lectur.io/subscribe ► WATCH MORE ON YOUTUBE: http://lectur.io/playlists ► LET’S CONNECT: • Facebook: https://www.facebook.com/lecturio.medical.education.videos • Instagram: https://www.instagram.com/lecturio_medical_videos • Twitter: https://twitter.com/LecturioMed
Products, Reactants, Energy, and Enzymes
 
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What is the difference between products and reactants? What is an enzyme-substrate complex and how do they make it possible for life to exist? We answer all these questions.
Views: 579 Erb Science
Derivation of Enzyme Kinetics for Competitive Inhibition
 
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Derives the rate expression for an enzyme reaction with a substrate to make a product where an inhibitor competes for the enzyme to form an inactive complex; this is competitive inhibition. The rate determining step approximation is used to determine the rate expression. Check out our screencasts on other types of inhibition: https://www.youtube.com/playlist?list=PL4xAk5aclnUj26ubv86C34HL703ZD_bsF Made by faculty at the University of Colorado Boulder, Department of Chemical & Biological Engineering. Check out our Kinetics/Reactor Design playlists: https://www.youtube.com/user/LearnChemE/playlists?view=50&flow=list&shelf_id=7 Check out our website for screencasts organized by popular textbooks: http://www.learncheme.com/screencasts/kinetics-reactor-design
Views: 13128 LearnChemE
Feedback Inhibition or End Product Inhibition of Enzymes
 
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This video explains Feed back inhibition or allosteric modulation of enzymes with animation. What are enzymes? What is an active site? How is it different from allosteric site?
Views: 35866 biologyexams4u
Enzymes: Mr. W's Enzyme Song
 
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On iTunes at https://itunes.apple.com/us/artist/glenn-wolkenfeld/id555040717 On Amazon at http://tinyurl.com/pvt5kbb Take the enzymes interactive quiz: http://www.sciencemusicvideos.com/quizzes/ Buy the video at http://www.teacherspayteachers.com/Store/Glenn-Wolkenfeld-1 Get curriculum at http://www.sciencemusicvideos.com On twitter, https://twitter.com/GlennWolkenfeld for bio-haiku and verse. This movie explains the biology of enzymes. My hope is that it will catalyze lots of learning. Enzymes LYRICS: They're the protein catalysts in every organism ENZYMES! Through enzymatic action your metabolism's driven ENZYMES! In staphylococcus, jellyfish, tarantulas and trees, They lower activation energy Enzymes, in you and me now ENZYMES! You got 'em in your cells where they do cellular digestion, ENZYMES! You got 'em in your mouth and in your stomach and intestines ENZYMES! The thing an enzyme acts upon is called a substrate. They fit like lock and key with complementary shape Enzymes, speed up reaction rates ENZYMES! An enzyme binds its substrate at its active site ENZYMES! Bound together in a complex where they snuggle so tight, ENZYMES! New bonds will form and break due to the active site's chemistry Reactants become products, it's the enzyme's specialty, Product gets release enzyme repeats its action readily ENZYMES! Like any molecule an enzyme's shape defines its function. ENZYMES! Environmental change that changes shape leads to malfunction, ENZYMES! Every enzyme has a pH where it catalyzes best, a pH change will set enzyme activity to rest. Enzymes are so sensitive they're easily upset ENZYMES! More heat until a certain point increases their efficiency ENZYMES! But too much heat denatures them destroying their activity ENZYMES! That's why a fever running high's a dangerous situation, All that heat can alter enzymatic conformation. Keep it 98.6 for enzyme optimization ENZYMES! Enzymes in saliva will break starch into glucose ENZYMES! If you lack the enzyme lactase then you won't enjoy milk lactose, ENZYMES! Tay-sachs, galactosemia and PKU disease, All caused by inherited enzyme deficiencies ENZYMES, they're what everybody needs ENZYMES!
Views: 262838 sciencemusicvideos
Enzymes and activation energy | Biomolecules | MCAT | Khan Academy
 
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Explore the role of enzymes in making a reaction more likely to happen quickly. By Ross Firestone. Created by Ross Firestone. Watch the next lesson: https://www.khanacademy.org/test-prep/mcat/biomolecules/enzyme-structure-and-function/v/the-induced-fit-model-of-enzyme-catalysis?utm_source=YT&utm_medium=Desc&utm_campaign=mcat Missed the previous lesson? https://www.khanacademy.org/test-prep/mcat/biomolecules/enzyme-structure-and-function/v/an-introduction-to-enzymes-and-catalysis?utm_source=YT&utm_medium=Desc&utm_campaign=mcat MCAT on Khan Academy: Go ahead and practice some passage-based questions! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s MCAT channel: https://www.youtube.com/channel/UCDkK5wqSuwDlJ3_nl3rgdiQ?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 192795 khanacademymedicine
What is substrate and enzyme
 
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What is substrate and enzyme
How Enzymes Work Animation
 
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This animation describes how enzymes workand the formation of an enzyme-substrate complex
Views: 43069 Aaron Chastain
Enzyme and Substrate -Lock and Key
 
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This is for education only! (It's my school hw) -- Created using PowToon -- Free sign up at http://www.powtoon.com/youtube/ -- Create animated videos and animated presentations for free. PowToon is a free tool that allows you to develop cool animated clips and animated presentations for your website, office meeting, sales pitch, nonprofit fundraiser, product launch, video resume, or anything else you could use an animated explainer video. PowToon's animation templates help you create animated presentations and animated explainer videos from scratch. Anyone can produce awesome animations quickly with PowToon, without the cost or hassle other professional animation services require.
Views: 4730 G connect
Derivation of Enzyme Kinetics for Uncompetitive Inhibition
 
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Derives the rate expression for an enzyme reaction with a substrate to make a product where an inhibitor competes for the enzyme-substrate complex to form an inactive complex; this is uncompetitive inhibition. The rate determining step approximation is used to determine the rate expression. Check out our screencasts on other types of inhibition: https://www.youtube.com/playlist?list=PL4xAk5aclnUj26ubv86C34HL703ZD_bsF Made by faculty at the University of Colorado Boulder, Department of Chemical & Biological Engineering. Check out our Kinetics/Reactor Design playlists: https://www.youtube.com/user/LearnChemE/playlists?view=50&flow=list&shelf_id=7 Check out our website for screencasts organized by popular textbooks: http://www.learncheme.com/screencasts/kinetics-reactor-design
Views: 7099 LearnChemE
Enzyme Function and Inhibition
 
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This video animation describes the basics of enzyme structure and function. This includes enzyme substrates and active sites, enzyme denaturation, and competitive and non-competitive inhibition. This entire case study can be found on the National Center for Case Study Teaching in Science website at the following address: http://sciencecases.lib.buffalo.edu/cs/collection/detail.asp?case_id=819&id=819
Labster Virtual Lab: Enzyme Kinetics Simulation
 
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Get your free trial here: https://www.labster.com/courses/LabsterX/ENK/2014/about ABOUT THE VIRTUAL LAB SIMULATION In the Enzyme Kinetics case, students learn how substrates are converted into products by catalysis. Additionally, students learn about the kinetics of enzyme involving the Michaelis-Menten equation and various rate constants. Content regarding DNA mutation and hyperactivity are also covered. In this lab, students run experiments using the enzyme Alcohol Dehydrogenase on a wild and mutant type to learn about Asian Glow syndrome. SUMMARIZED LEARNING OUTCOMES - Learn the experimental design of enzyme kinetics - Understand the Michaelis-Menten model of enzyme kinetics - Analyze spectrophotometer data and calculate Km and Vmax - Understand that kinetics of an enzyme can be modified by genetic mutations - Understand inhibition kinetics by using several types of inhibitors DETAILED LAB DESCRIPTION Using spectrophotometer to measure enzyme reaction Students access a fully equipped workbench where they prepare the Alcohol Dehydrogenase reaction and measure the product of Acetylaldehyde using a spectrophotometer. Students learn about the concept of spectrophotometer, how to prepare a master mix and how to calculate dilution. Students prepare a reaction in a 1 ml cuvette and measure the amount of product formed using the spectrophotometer. Supplementary 3D animation illustrates what happens on the molecular level when the substrate and co-factor enter the active site; dialog explains the situation as product is formed. Students are also prompted with quiz questions during the 3D animation to test their understanding on concepts. In the interactive animation, students identify the substrate by clicking on the different molecules. For every measurement, students receive a progress curve displaying amounts of product formed over time. At the end of the experiment, results are presented as an Excel spreadsheet. Students must analyze their outcome data and plot their own Michaelis-Menten graph to find the Km and Vmax for each enzyme. By comparing Km and Vmax values of the wild type vs. mutant Alcohol Dehydrogenase, students will be able to understand the Asian Glow syndrome. With the newly added module of enzyme inhibition, students are asked to perform different enzyme inhibition experiments using three different inhibitors. To begin, Students measure product formation using several inhibitor concentrations, extract the data, create their own Lineweaver-Burk plot and solve the Ki. We have recently upgraded the Enzyme Kinetics lab by implementing a mathematically based simulator. This provides students with a larger flexibility in conducting their experiments. Students can change parameters such as substrate concentrations, enzyme concentrations, temperature or pH and receive the corresponding results. In this semi-guided module, students may experiment with different parameters in order to find the optimal temperature and pH to reach the highest initial reaction rate. Upon completing the Enzyme Kinetics lab, students will be familiar with the kinetics of enzyme Alcohol Dehydrogenase, performing the experiment as well as analyzing the data outcome. By using a real life example of Alcohol Dehydrogenase and the Asian Glow syndrome, students will be able to understand about enzyme kinetics and relate it to their own daily life.
Views: 5091 Labster
Enzyme inhibition types and applications of enzyme inhibition
 
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Enzyme inhibition biochemistry lecture - This lecture explains about types of enzyme inhibition in reaction. This enzyme biochemistry lecture also explains the application of enzyme inhibition in chemical reactions. Enzyme inhibition are of different type such as competitive inhibition, uncompetitive inhibition, noncompetitive inhibition and mixed inhibition. All types of enzyme inhibition mechanism is explained with graph and equation in this biochemistry lecture. For more information, log on to- http://www.shomusbiology.com/ Get Shomu's Biology DVD set here- http://www.shomusbiology.com/dvd-store/ Download the study materials here- http://shomusbiology.com/bio-materials.html Remember Shomu’s Biology is created to spread the knowledge of life science and biology by sharing all this free biology lectures video and animation presented by Suman Bhattacharjee in YouTube. All these tutorials are brought to you for free. Please subscribe to our channel so that we can grow together. You can check for any of the following services from Shomu’s Biology- Buy Shomu’s Biology lecture DVD set- www.shomusbiology.com/dvd-store Shomu’s Biology assignment services – www.shomusbiology.com/assignment -help Join Online coaching for CSIR NET exam – www.shomusbiology.com/net-coaching We are social. Find us on different sites here- Our Website – www.shomusbiology.com Facebook page- https://www.facebook.com/ShomusBiology/ Twitter - https://twitter.com/shomusbiology SlideShare- www.slideshare.net/shomusbiology Google plus- https://plus.google.com/113648584982732129198 LinkedIn - https://www.linkedin.com/in/suman-bhattacharjee-2a051661 Youtube- https://www.youtube.com/user/TheFunsuman Thank you for watching the lecture on enzyme inhibition mechanism, types and role of enzyme inhibition in enzymatic reactions.
Views: 33168 Shomu's Biology
What are Enzymes - How Do They Work?
 
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http://www.amazon.com/NOW-Foods-Super-Enzymes-Capsules/dp/B0013OXKHC/ref=sr_1_2_s_it?s=hpc&ie=UTF8&qid=1460473202&sr=1-2: Enzymes are biological catalysts, mainly proteins, generated by an organism to speed up chemical reactions. They have an active site on which the substrate is attached, and then broken up or joined. You can find more about Enzymes products from: http://www.amazon.com/NOW-Foods-Super-Enzymes-Capsules/dp/B0013OXKHC/ref=sr_1_2_s_it?s=hpc&ie=UTF8&qid=1460473202&sr=1-2
Views: 538070 MTS Video Marketing
Steady states and the Michaelis Menten equation | Biomolecules | MCAT | Khan Academy
 
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Created by Ross Firestone. Watch the next lesson: https://www.khanacademy.org/test-prep/mcat/biomolecules/enzyme-kinetics/v/enzymatic-inhibition-and-lineweaver-burke-plots?utm_source=YT&utm_medium=Desc&utm_campaign=mcat Missed the previous lesson? https://www.khanacademy.org/test-prep/mcat/biomolecules/enzyme-structure-and-function/v/enzymes-and-their-local-environment?utm_source=YT&utm_medium=Desc&utm_campaign=mcat MCAT on Khan Academy: Go ahead and practice some passage-based questions! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s MCAT channel: https://www.youtube.com/channel/UCDkK5wqSuwDlJ3_nl3rgdiQ?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 491658 khanacademymedicine
Feedback Inhibition of Biochemical Pathways [HD Animation]
 
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Feedback Inhibition of Biochemical Pathways Animation #Please → Like, comment, share and subscribe 👍🏻❤️
11.  Kevin Ahern's Biochemistry - Enzymes III
 
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1. Contact me at [email protected] / Friend me on Facebook (kevin.g.ahern) 2. Download my free biochemistry book at http://biochem.science.oregonstate.edu/biochemistry-free-and-easy 3. Take my free iTunes U course at https://itunes.apple.com/us/course/biochemistry/id556410409 4. Check out my free book for pre-meds at http://biochem.science.oregonstate.edu/biochemistry-free-and-easy 5. Lecturio videos for medical students - https://www.lecturio.com/medical-courses/biochemistry.course 6. Course video channel at http://www.youtube.com/user/oharow/videos?view=1 7. Check out all of my free workshops at http://oregonstate.edu/dept/biochem/ahern/123.html 8. Check out my Metabolic Melodies at http://www.davincipress.com/ 9. My courses can be taken for credit (wherever you live) via OSU's ecampus. For details, see http://ecampus.oregonstate.edu/soc/ecatalog/ecourselist.htm?termcode=all&subject=BB 10. Course materials at http://oregonstate.edu/instruct/bb450 Highlights of Enzymes III Lecture 1.Chemicals, such as DIPF and iodoacetate, covalently (and irreversibly) bind to the side chains of specific amino acids (serine and cysteine, respectively) and if these side chains are essential for the catalytic action of the enzyme, the enzyme will not catalyze reactions after being treated with these chemicals. 2. Penicillin is a substance that resembles the substrate of an enzyme in bacteria that helps make the bacterial cell wall. When it binds to the enzyme, it inactivates the enzyme by covalently bonding to the active site, thus destroying the enzyme (and killing the bacterium containing it). An inhibitor of this type is known as a suicide inhibitor. Highlights Catalytic Mechanisms 1. Proteases catalyze the hydrolysis of peptide bonds in polypeptides. They are usually fairly specific for certain amino acids and cut at or near those amino acids. 2. Chymotrypsin is a protease whose activity has been closely studied. Conveniently, the activity of chymotrypsin can be studied using an artificial substrate which, when cleaved by the enzyme, releases a yellow product. 3. When the release of the colored substrate by the enzyme is studied, it appears to occur in two different rates. First there is a VERY rapid release of the colored substrate. After that initial burst of activity, the remaining yellow color is released slowly. 4. The reason appears to be that the reaction catalyzed occurs in two steps. The first step cleaves the bond to produce the yellow product, which is rapidly released. The other product of this reaction is the remainder of the substrate that is covalently linked to the enzyme. In order for the enzyme to bind another substrate molecule and release more yellow color, it must first release the covalently bound molecule. This step occurs slowly and explains why subsequent yellow molecules are released slowly - after the initial one is released, the enzyme must remove the covalently bound molecule, bind a new substrate, and cut the substrate and the continue the process repeatedly. 5. Chymotrypsin is an example of a protease that employs reactive serine in its active site. Such an enzyme is called a serine protease. Treatment of chymotrypsin with DIPF, which covalently links to serines, inactivates the enzyme. 6. Serine proteases form covalent intermediates with their polypeptide substrates. The first step involves nucleophilic attack of an alkoxide ion on the polypeptide substrate to form an acyl-enzyme intermediate. Formation of this intermediate results in cleavage of the peptide bond and release of the first polypeptide fragment. The acyl-enzyme intermediate is resolved by addition of water to release the other portion of the original polypeptide along with regeneration of the original enzyme active site. This last step occurs relatively slowly. 7. In the active site of chymotrypsin (and other serine proteases) is a so-called catalytic triad of amino acids that includes a serine hydrogen bonded to a histidine. The histidine is, in turn, hydrogen bonded to an aspartic acid residue in the active site. Each of the hydrogen bonds of the catalytic triad is important in the catalytic mechanism. The nucleophilic alkoxide ion on serine is made possible ultimately by interactions in the catalytic triad and these hydrogen bonds.
Views: 8331 Kevin Ahern
Enzyme Inhibition (Part 1 of 3) - Competitive Inhibitors
 
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Moof's Medical Biochemistry Video Course: http://moof-university.thinkific.com/courses/medical-biochemistry-for-usmle-step-1-exam Questions Answered in This Video: - What are competitive inhibitors, and what is mechanism by which they act? - How do competitive inhibitors affect the values of KM and VMAX? - How do competitively inhibited reactions look on the hyperbolic graph and Lineweaver-Burk plot? Don't forget to LIKE, COMMENT, and SUBSCRIBE: http://www.youtube.com/subscription_center?add_user=MoofUniversity INFORMATION ABOUT TUTORING: http://www.moofuniversity.com/tutoring/ TO SUPPORT MOOF UNIVERSITY WITH A FINANCIAL CONTRIBUTION: http://www.moofuniversity.com/support-moof/ INSTAGRAM: https://instagram.com/moofuniversity/ FACEBOOK: https://www.facebook.com/pages/Moof-University/1554858934727545 TWITTER: https://twitter.com/moofuniversity Video Content Summary: Competitive inhibitors "compete" with substrate for binding the enzyme's active site. Free enzyme will bind either the substrate OR the competitive inhibitor. It cannot bind both at the same time. If the enzyme binds the substrate, the enzyme-substrate complex forms, and the enzyme can convert the substrate into product. If, however, a competitive inhibitor binds the active site, the enzyme-competitive inhibitor complex forms, which cannot proceed towards products, for the simple reason that the competitive inhibitor impedes the ability of the substrate to bind to the enzyme. Since a competitive inhibitor blocks the substrate from binding, the competitive inhibitor essentially lowers the affinity of enzyme for the substrate. Thus increasing the KM. Despite this, VMAX can still be reached with a high enough substrate concentration. If the substrate concentration is sufficiently high, the substrates will out-compete the competitive inhibitor for binding at the active site, thus effectively overcoming the effects of the inhibitor. The effects of a competitive inhibitor on an enzyme-catalyzed reaction are depicted in a variety of ways in the video, and it is shown what happens to the hyperbolic graph and the Lineweaver-Burk plot, otherwise known as the double reciprocal plot.
Views: 13365 Moof University
What is the Lock and key theory of enzyme action?
 
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Here the larger enzyme molecule comes in contact with smaller substrate molecule to form an intermediate complex. This intermediate complex or enzyme substrate complex soon breaks to release enzyme and product of biochemical reaction. Mode of enzyme action. Biosynthetic reaction. Here the active side establish contact with substrate molecule to form products of biochemical reaction. Mode of enzyme action. The enzyme has distinct cavities specially designed for specific substrate molecules with proper geometric shape that can hit properly.
Views: 1582 Pearson India
Ahern's Biochemistry #10 - Enzymes 2
 
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Contact me at [email protected] / Friend me on Facebook (kevin.g.ahern) Highlights Enzymes II 1. Velocity of an enzymatic reaction is measured as the concentration of product formed per time. It can be estimated in a V vs. [S] plot. Maximum velocity (Vmax) occurs in a reaction when the enzyme is saturated with substrate. Vmax depends on the amount of enzyme used to measure it. It is NOT a constant for an enzyme. 2. We define Km as the substrate concentration that gives Vmax/2. Whereas the Vmax varies, depending on the amount of enzyme that one uses, the Km is a constant for a given enzyme for its substrate. 3. The higher the Km of an enzyme, the LOWER its affinity for its substrate. This is because a high Km means that it takes a LOT of substrate before the enzyme gets to Vmax/2. Km is frequently referred to as the affinity of the enzyme for a substrate, though that is not 100% correct. Nevertheless, we say that a high Km is consistent with a low affinity of enzyme for substrate and conversely, that a low Km is consistent with a high affinity of enzyme for substrate. 4. If one lets a reaction go for a long time, it will reach equilibrium. At equilibrium, the relative concentration of products and reactants do not change. Initial velocities of reactions are therefore measured so as to avoid allow the product to accumulate and favor the reverse reaction. 5. Lineweaver-Burk plots are alternative plots of V vs S data obtained by taking the inverse of each and plotting it, thus making a 1/V vs 1/[S] plot (also called a double reciprocal plot). 6. On a Lineweaver-Burk plot, the Y intercept is 1/Vmax and the X intercept is -1/Km. 7. The catalytic actions of enzymes appear to be related to their ability to be at least slightly flexible. Originally, Fischer proposed a model of catalysis called the Lock and Key model. It described enzymes as inflexible and the substrate as like a key fitting into a lock. While substrates do, in fact, fit into enzymes somewhat like a key, the enzyme is NOT inflexible. 8. Koshland's model of enzyme action, called the Induced Fit model says that not only does the enzyme change the substrate (via catalysis), but the substrate also changes the enzyme shape upon binding. This transient change of enzyme shape is important for catalysis because it may bring together molecular groups (such as a phosphate and a sugar) that may not be close together in the enzyme prior to the change in enzyme shape. Remember that enzymes also work by orienting substrates together in the proper way to maximize their likelihood of bouncing together in a way that leads to making a bond. 9. Chemical changes brought about by catalysis facilitate a last change in enzyme shape to allow for the release of the products. When this happens, the enzyme returns to its original shape and remains unchanged by acting to catalyze the reaction. 10. In contrast to Vmax, Kcat is a constant for an enzyme. It is also known as the turnover number and corresponds to the number of molecules of product made per molecule of enzyme per second. 1000/second means 1000 molecules of product per molecule of enzyme per second. 11. "Perfect" enzymes are enzymes that have evolved to the point where any additional mutation will reduce their ability to catalyze reactions. They are not common. Perfect enzymes have a very high ratio of Kcat/Km and are such that the only thing that inhibits their ability to function more efficiently is the rate of diffusion of substrate in water.
Views: 5385 Kevin Ahern
Catalytic Strategies
 
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This course is part of a series taught by Kevin Ahern at Oregon State University on General Biochemistry. For more information about online courses go to http://ecampus.oregonstate.edu/ http://www.youtube.com/playlist?list=PL850269AA28EF394A 1. Proteases catalyze the hydrolysis of peptide bonds in polypeptides. They are usually fairly specific for certain amino acids and cut at or near those amino acids. 2. Chymotrypsin is a protease whose activity has been closely studied. Conveniently, the activity of chymotrypsin can be studied using an artificial substrate which, when cleaved by the enzyme, releases a yellow product. 3. When the release of the colored substrate by the enzyme is studied, it appears to occur in two different rates. First there is a VERY rapid release of the colored substrate. After that initial burst of activity, the remaining yellow color is released slowly. 4. The reason appears to be that the reaction catalyzed occurs in two steps. The first step cleaves the bond to produce the yellow product. The product of this release is that the remainder of the substrate is covalently linked to the enzyme. In order for the enzyme to bind another substrate molecule and release more yellow color, it must first release the covalently bound molecule. This step occurs slowly and explains why subsequent yellow molecules are released slowly - after the initial one is released, the enzyme must remove the covalently bound molecule, bind a new substrate, and cut the substrate and the continue the process repeatedly. 5. Chymotrypsin is an example of a protease that employs reactive serine in its active site. Such an enzyme is called a serine protease. Treatment of chymotrypsin with DIPF, which covalently links to serines, inactivates the enzyme. 6. Serine proteases form covalent intermediates with their polypeptide substrates. The first step involves nucleophilic attack of an alkoxide ion on the polypeptide substrate to form an acyl-enzyme intermediate. Formation of this intermediate results in cleavage of the peptide bond and release of the first polypeptide fragment. The acyl-enzyme intermediate is resolved by addition of water to release the other portion of the original polypeptide along with regeneration of the original enzyme active site. This last step occurs relatively slowly. 7. In the active site of chymotrypsin (and other serine proteases) is a so-called catalytic triad of amino acids that includes a serine hydrogen bonded to a histidine. The histidine is, in turn, hydrogen bonded to an aspartic acid residue in the active site. Each of the hydrogen bonds of the catalytic triad is important in the catalytic mechanism. The nucleophilic alkoxide ion on serine is made possible ultimately by interactions in the catalytic triad and these hydrogen bonds. 8. The catalytic triad is not unique to chymotrypsin. The serine protease known as subtilisin also has the same catalytic triad and employs a similar mechanism. 9. Besides the catalytic triad, the enzyme has two other important sites to consider. The first is the oxyanion hole that stabilizes a tetrahedral intermediate that arises during the catalysis. The second, called as S1 pocket, is where the substrate binds. Both the oxyanion hole and the S1 pocket are adjacent to the active site (catalytic triad). 10. The S1 pocket determines a serine protease's specificity. The S1 pocket of chymotrypsin is hydrophobic and relatively large, allowing it to bind phenylalanine, for example. Remember that chymotrypsin cuts adjacent to phenylalanine (among other hydrophobic amino acids). The S1 pocket of trypsin, for example has a negatively charged group in the bottom, allowing it to bind to lysine or arginine. 11. Other proteases include cysteine proteases (use cysteine and histidine in the active site), aspartyl proteases (use aspartic acids and water in the active site) metalloproteases (use a metal ion - usually zinc - and water in the active site). 11. Carbonic anhydrase is an enzyme that catalyzes the joining of carbon dioxide and water to form carbonic acid. 12. A zinc ion (held in place by three histidines in the active site of carbonic anhydrase) plays an important role in the catalysis of the enzyme by binding a water molecule. A subsequent loss of a proton by water is necessary for catalysis. Notably, the enzyme has maximal activity at a high pH (where protons are easily removed) and a lower activity in an acidic pH (6.0). 13. The limiting step in the action of carbonic anhydrase is the abstraction of the proton from water. Buffers and/or bases help facilitate this and thus speed the reaction.
Target A2.2: Chemical Reactions & Enzymes
 
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Enzyme. Substrate. PRODUCT!!
Views: 1500 MrAdamCarlson
Enzyme
 
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Enzymes enable molecules called substrates to undergo a chemical change to create new molecules called products. Each substrate fits in a specific area of the enzyme called the active site similar to lock and key mechanism.
Views: 275639 kosasihiskandarsjah
Enzymes II
 
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This course is part of a series taught by Kevin Ahern at Oregon State University on General Biochemistry. For more information about online courses go to http://ecampus.oregonstate.edu/ http://www.youtube.com/playlist?list=PL850269AA28EF394A Also check out the free textbook "Biochemistry Free and Easy" at: http://biochem.science.oregonstate.edu 1. The Gibbs free energy is the energy available to do useful work in reactions. The change in the Gibbs free energy for a reaction is important because it determines whether a reaction is favored, unfavored, or at equilibrium. 2. Thus, when the Gibbs free energy change is negative, the reaction in question goes forward as written, but when the Gibbs free energy change is positive, the reaction goes in reverse. 3. A related term to G is G°', which is the Standard Gibbs Free Energy change. This refers to the Gibbs Free Energy change for a reaction under standard conditions. Since most reactions occur at non-standard conditions, G is much more useful than G°'. In fact, the sign of G°' does NOT tell the direction of a reaction, except under standard conditions. 4. Chemical reactions require activation energy (I'll call it G+ here) in order to get started. Catalysts (both enzymes and non-biological catalysts) act by lowering G+. Catalysts DO NOT CHANGE G. All they do is lower the energy required to activate the reaction. While enzymes speed reactions immensely, they therefore DO NOT CHANGE THE OVERALL REACTION CONCENTRATION AT EQUILIBRIUM. They simply allow the reaction to get to equilibrium faster. 5. G is affected by the concentration of reactants and products of a reaction by the following equation G = G°' + RTln[Products/Reactants] Thus, as product concentrations increase, the G will become more positive. 6. If one performs an experiment in which a fixed amount of enzyme is added to 20 different tubes, each containing a different amount of substrate (molecule that the enzyme catalyzes the reaction on) and then lets the reaction in each tube go for a fixed amount of time, one will create varying amounts of product when the tubes are analyzed. The greatest amount of product will be found in the tube which had the greatest amount of substrate. If one measures the concentrations of each product and divides by the time the reaction occurred, one obtains a velocity for each reaction. A plot of the velocity versus the substrate concentration (V versus S) from the experiment looks like the binding curve of myoglobin for oxygen - hyperbolic. 7. Velocity of an enzymatic reaction is measured as the concentration of product formed per time. 8. If one lets a reaction go for a long time, it will reach equilibrium. At equilibrium, the relative concentration of products and reactants do not change. Initial velocities of reactions are therefore measured so as to avoid allow the product to accumulate and favor the reverse reaction. 9. The catalytic action of enzymes appears to be related to their ability to be at least slightly flexible. Originally, Fischer proposed a model of catalysis called the Lock and Key model. It described enzymes as inflexible and the substrate as like a key fitting into a lock. While substrates do, in fact, fit into enzymes somewhat like a key, the enzyme is NOT inflexible. 10. Koshland's model of enzyme action, called the Induced Fit model says that not only does the enzyme change the substrate (via catalysis), but the substrate also changes the enzyme shape upon binding. This transient change of enzyme shape is important for catalysis because it may bring together molecular groups (such as a phosphate and a sugar) that may not be close together in the enzyme prior to the change in enzyme shape. Remember that enzymes also work by orienting substrates together in the proper way to maximize their likelihood of bouncing together in a way that leads to making a bond. 11. Chemical changes brought about by catalysis facilitate a last change in enzyme shape to allow for the release of the products. When this happens, the enzyme returns to its original shape and remains unchanged by acting to catalyze the reaction. 12. At very high concentrations of substrate, the enzyme gets overwhelmed (saturated) and a maximum velocity (Vmax) is approached. If one adds more enzyme, a higher maximum velocity will be reached. Vmax thus doesn't tell very much about an enzyme because its value depends on the amount of enzyme we use. 13. Km is the substrate concentration that gives an enzyme half its Vmax. Note that Km is a CONCENTRATION. 14. We define Km as the substrate concentration that gives Vmax/2. Whereas the Vmax varies, depending on the amount of enzyme that one uses, the Km is a constant for a given enzyme for its substrate.
Ahern's BB 350 at OSU - 8. Enzymes I
 
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Contact me at [email protected] Facebook friend me at https://www.facebook.com/kevin.g.ahern 1. 2D gel electrophoresis involves two separations in two dimensions. The first involves separation on the basis of charge. The second involves placing the tube containing the separated charged molecules, adding SDS, and then running the contents on SDS-page. The resulting gel has molecules separated by size in the vertical direction and by charge in the horizontal direction. 2. HPLC (High Performance Liquid Chromatography) is another technique for separating molecules/proteins. It works by separating on the basis of polarity. Molecules that are the least polar elute from the column last, whereas molecules that are the most polar elute first. 3. Proteins can be broken into smaller pieces using enzymes like trypsin (cuts lysine or arginine), chymotrypsin, and cyanogen bromide (breaks at methionines). Highlights Enzymes I 1. Enzymes catalyze reactions up to many trillion of times faster than the same reactions without any catalysts. 2. Enzymes work by reducing the activation energy required for a reaction to occur. Because enzymes lower that "starting" energy requirement, they make the reaction easier to occur and thus speed them up. 3. Note also (important) that enzymes do NOT change the free energy difference between the beginning reactants and the end products. Thus, enzymes do not change the overall energy of a reaction - only the energy required for the transition state. 4. A "substrate" is a molecule bound by an enzyme which it catalyzes a reaction upon. Substrates bind specific binding sites on enzymes that resemble their structure. An "active site" of an enzyme is a site on an enzyme where the reaction it catalyzes occurs. 5. As one increases the amount of substrate for an enzymatic reaction, the velocity of the reaction (concentratioin of product made per time) increases. If one uses more enzyme, one produces a faster velocity. 6. An enzymatic reaction's maximum velocity (Vmax) is the limit (maximum) of a plot of the velocity versus the substrate concentration. Enzymatic reactions reach maximum velocity when the enzyme is saturated with substrate. Plots of enzyme velocities versus substrate concentration are called hyperbolic. 7. Vmax varies with the amount of enzyme used in a reaction. To account for the amount of enzyme in a reaction, Kcat (also called turnover number) is used. Kcat is equal to Vmax/[Enzyme]. Because the concentration of enzyme is taken into account in this equation, Kcat does NOT vary with the amount of enzyme used and is therefore a constant for an enzyme. Kcat is equal to the number of molecules of product made per enzyme per unit time. A Kcat of 5/second means that that enzyme makes five molecules of product per molecule of enzyme per second. 8. A very important number that does NOT vary according to the quantity of enzyme used (that is to say that it is a constant for a given enzyme) is the Km (the Michaelis constant). Km turns out to be the concentration of substrate required to get an enzymatic reaction to half maximum velocity. Km is a constant for any given enzyme and provides a measure of an enzyme's "affinity" for its substrate. An enzyme with a high Km has a low affinity for its substrate. An enzyme with a low Km has a high affinity for its substrate. Note that Km is NOT Vmax/2. Instead, it is the substrate concentration required to get a reaction to Vmax/2.
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Enzyme Inhibition (Part 2 of 3) - Noncompetitive Inhibitors
 
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Moof's Medical Biochemistry Video Course: http://moof-university.thinkific.com/courses/medical-biochemistry-for-usmle-step-1-exam Questions Answered in This Video: - What are noncompetitive inhibitors, and what is mechanism by which they act? - How do noncompetitive inhibitors affect the values of KM and VMAX? - How do noncompetitively inhibited reactions look on the hyperbolic graph and Lineweaver-Burk plot? Don't forget to LIKE, COMMENT, and SUBSCRIBE: http://www.youtube.com/subscription_center?add_user=MoofUniversity INFORMATION ABOUT TUTORING: http://www.moofuniversity.com/tutoring/ TO SUPPORT MOOF UNIVERSITY WITH A FINANCIAL CONTRIBUTION: http://www.moofuniversity.com/support-moof/ INSTAGRAM: https://instagram.com/moofuniversity/ FACEBOOK: https://www.facebook.com/pages/Moof-University/1554858934727545 TWITTER: https://twitter.com/moofuniversity Video Content Summary: Noncompetitive inhibitors, unlike competitive inhibitors, do not bind at the active site. They bind a site elsewhere on the enzyme. Thus, they can bind free enzyme OR the enzyme-substrate complex. So, the enzyme-substrate complex, the enzyme-noncompetitive inhibitor complex, and the enzyme-substrate-noncompetitive inhibitor complex can all potentially form. Of course, as long as the noncompetitive inhibitor is bound, the enzyme will not be able to convert substrate into product. Since a noncompetitive inhibitor binds at a site other than the active site and does not have an impact on whether or not substrate can bind, the affinity of enzyme for substrate is not changed, and the KM value remains unchanged. However, the effect of a noncompetitive inhibitor cannot be overcome by increasing substrate concentration, and as long as there are noncompetitive inhibitors present, there will be a smaller number of functional enzymes, relative to an uninhibited case. Less functional enzymes means lower rate of catalysis and a lower VMAX. The effects of a noncompetitive inhibitor on an enzyme-catalyzed reaction are depicted in a variety of ways in the video, and it is shown what happens to the hyperbolic graph and the Lineweaver-Burk plot, otherwise known as the double reciprocal plot.
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What Is The Substrate Of The Enzyme Lactase?
 
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The activity of lactase westminster collegeenzymes and lactose intolerance science take out. What is the substrate and product of enzyme lactase? . Students will observe the actions of enzyme and how shape is important to reactions lactase an produced by many organisms. Starch (polysaccharides)sucrase, maltase, lactase. It is located in the brush border of catalytic mechanism d lactose hydrolysis retains substrate anomeric configuration products. Explain the use of lactase in production lactose free milk region enzyme which a substrate binds to and catalyses chemical reaction some people lack cannot break down leading is protein; Enzymes are proteins, but not all proteins enzymes. What does lactase substrate mean? 2 answers quora what mean is an enzyme which hydrolyses lactose into galactose. 3) boiled milk enzyme (does boiling the substrate stop the enzyme from working? . Therefore the substrate is lactose this lab will examine specificity of an enzyme (lactase) to a specific (lactose). Lactase enzyme lab learn nc learnnc lp pages 3398 url? Q webcache. Therefore the substrate is lactose. Googleusercontent search. Enzymes ib guidesbiology lesson 17 proteins as flashcards quizletkinetic study of the enzyme lactase. What two products are formed when the enzyme lactase digests lactose? . Lactase substrate mean? 2 answers quora. What is the name of molecule that substrate? 5. This enzyme has two active sites, one being site region on the surface of an to which substrates bind and 3. What does lactase substrate mean? 2 answers quora. Define the terms enzyme and substrateexplain result of we will test effect temperature on how well lactase works. The lactose substrate binds to the lactase enzyme form an of amylase. By the end of this lab, examine specificity an enzyme to a specific substrate oct 1, 1992 lactase phlorizin hydrolase is disaccharidase present in small intestine mammals. Yahoo substrate specificity of small intestinal lactase wiley online librarysubstrate. What word ending is 6. Lactase is an enzyme which hydrolyses lactose into galactose. Assessment of the ib biology notes 3. It is a complex carbohydrate made of question 4what structure a? Substrateenzyme where lactose broken down into glucose and galactose by the enzyme lactase. 23)to the memory of professor the purpose of this lab is to explore the properties of the enzyme lactase. Lactase enzyme by rachel zeller on prezi. Enzyme that breaks down disaccharides into in the presence of lactase, lactose is cleaved and reduced to its subunits substrate(s) reactant(s) reaction are bound by enzyme kinetic study lactase a specific intestinal 8 galactosidase re hydrolysis this substrate catalyzed commerical competing substrates on activity lactasethe student will be able 1. Dec 17, 2013 lactase enzyme catalyst lactose is the substrate that breaks down. Lactase enzyme lab learn ncenzymes and reaction rates nau. While the details of mechanism are enzyme attaches to substrate molecule at a specifi
Enzymes I - Kevin Ahern's BB 450 Lecture #9 2016
 
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Contact me at [email protected] Facebook friend me at https://www.facebook.com/kevin.g.ahern 1. A western blot is a technique to identify and, to a limited extent, quantitate a protein separated on a gel 2. The technique involves a) SDS-PAGE; b) transfer of the separated proteins to a membrane; c) affixing the transferred proteins to the membrane; d) treatment of the membrane proteins with an antibody specific to the protein of interest; e) visualizing the antibody-bound to the protein. Enzymes 1. Enzymes are proteins that catalyze reactions. 2. Enzymes are capable of speeding reactions quadrillions of times faster than the same reactions would occur in the absence of enzymes. 3. Substrate(s) are molecules that are affected by the catalysis of the enzyme 4. Substrates bind to a substrate binding site on an enzyme and this overlaps with the active site - the place on the enzyme where a reaction occurs. 5. Steps in catalysis include a) binding of the substrate(s) by the enzyme to form the ES complex; b) reaction between the substrate(s) at the active site (ES* complex); c) completion of the reaction (EP complex), and d) release of the product(s) by the enzyme. 6. The enzyme undergoes a change upon binding the substrate(s) and that is the key to the many fold enhancement of the reaction by the enzyme. 7. Enzymes exhibit binding specificity - substrates have specific shapes and though a range of shapes may be accepted, the range is usually quite narrow. 8. Enzymes are flexible and their flexibility plays a major role in catalysis 9. Changes in enzyme shape and/or changes resulting from substrate binding affect/change the electronic environment of the enzyme and ultimately the active site. 10. Non-proteinaceous molecules that bind to enzymes and help the enzymes to catalyze reactions are called coenzymes. 11. Two models of enzyme action are a) the Fischer Lock and Key model and b) the Koshland Induced Fit model 12. The Fischer Lock and Key model states that a substrate fits into an enzyme like a key into a lock. It helps describe the specificity of substrate binding, but nothing of the mechanism of catalysis. 13. The Koshland Induced Fit model says that an enzyme changes substrate(s) into product(s) and that the substrate(s) transiently changes an enzyme, thus providing a mechanism of catalysis. 14. Changes in the enzyme on substrate binding create "tensions" or "stresses" that help to stimulate the catalytic process. These tensions can be electronic or mechanical in nature. 15. Chemical reactions require activation energy (I'll call it G+ here) in order to get started. Catalysts (both enzymes and non-biological catalysts) act by lowering G+. Catalysts DO NOT CHANGE G. All they do is lower the energy required to activate the reaction. While enzymes speed reactions immensely, they therefore DO NOT CHANGE THE OVERALL REACTION CONCENTRATION AT EQUILIBRIUM. They simply allow the reaction to get to equilibrium faster. 16. Reactions catalyzed by enzymes are reversible. 17. At equilibrium, the concenration of reacants and products do not change. ONLY if G°' is zero can one say that [A] = [B] for a reaction A GOES TO B. 18. Reactions can be a) single substrate - single product; b) single substrate - multiple product; c) multiple substrates - single products; and d) multiple substrates - multiple products. 19. Multiple substrate - multiple product reactions are of three types a) ordered - order of binding of substrates required for reaction - lactate dehydrogenase example b) random - order of binding of substrates not required for reaction - creatine kinase example c) Ping-Pong - the enzyme flips between two different states in its catalytic action - transaminase example 19. For an enzyme reaciton, E+S GOES TO ES GOES TO ES* GOES TO EP GOES TO E+P 20. For a simple case of ES GOES TO E+P, then Kcat is the rate constant for the reaction and is what we aim to determine.
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