...------------------------------------------------- Enzyme From Wikipedia, the free encyclopedia (Redirected from Enzymology) Enzymes /ˈɛnzaɪmz/ are macromolecular biological catalysts. Enzymes accelerate, or catalyze, chemical reactions. The molecules at the beginning of the process are called substrates and the enzyme converts these into different molecules, called products. Almost all metabolic processes in the cell need enzymes in order to occur at rates fast enough to sustain life.[1]:8.1 The set of enzymes made in a cell determines which metabolic pathways occur in that cell. The study of enzymes is called enzymology. Enzymes are known to catalyze more than 5,000 biochemical reaction types.[2] Most enzymes are proteins, although a few are catalytic RNA molecules. Enzymes' specificity comes from their uniquethree-dimensional structures. Like all catalysts, enzymes increase the rate of a reaction 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.[3][4] 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...
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...Enzymes are biological catalysts. There are about 40,000 different enzymes in human cells, each controlling a different chemical reaction. They increase the rate of reactions by a factor of between 106 to 1012 times, allowing the chemical reactions that make life possible to take place at normal temperatures. They were discovered in fermenting yeast in 1900 by Buchner, and the name enzyme means "in yeast". As well as catalysing all the metabolic reactions of cells (such as respiration, photosynthesis and digestion), they may also act as motors, membrane pumps and receptors. Enzymes are proteins, and their function is determined by their complex structure. The reaction takes place in a small part of the enzyme called the active site, while the rest of the protein acts as "scaffolding". This is shown in this diagram of a molecule of the enzyme trypsin, with a short length of protein being digested in its active site. The amino acids around the active site attach to the substrate molecule and hold it in position while the reaction takes place. This makes the enzyme specific for one reaction only, as other molecules won't fit into the active site – their shape is wrong. Many enzymes need cofactors (or coenzymes) to work properly. These can be metal ions (such as Fe2+, Mg2+, Cu2+) or organic molecules (such as haem, biotin, FAD, NAD or coenzyme A). Many of these are derived from dietary vitamins, which is why they are so important. The complete active enzyme with its cofactor...
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...Wilbon 3/22/15 Enzyme lab report Determining the properties of an Enzyme Introduction: Enzymes are proteins that acts as catalysts for reactions. This means that enzymes lower the activation energy essential for a reaction to take place, allowing a specific reaction to occur much quicker and easier. Certain enzymes only lower the activation energy for certain reactions, and enzymes are shape precise. The distinctive folds of the amino acid chains that make up an enzyme result in the formation of a precisely shape active site. When the reactants of a reaction, substrates, fit seamlessly into the active site of an enzyme, the enzyme is then able to catalyze the reaction. The activity of enzymes is affected by the concentration of enzymes current and the concentration of substrate current. As the amount of enzyme present increases, the rate of reaction increases. Most enzymes need specific environmental conditions to be met in order for them to function properly and efficiently. These conditions include the pH level, temperature, and the inhibitor. If the ideal conditions for an enzyme are altered, the enzyme may denature, or change its shape, resulting in deactivation. As a result, the enzyme activity would be that it would no longer be able to catalyze the reaction, and the reaction rate would significantly decrease...
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...Temperature can affect a lot of different factors hence its effect on enzyme activity is very complex. It affects the speeds of molecules, the activation energy of the catalytic reaction and the thermal stability of the enzyme and substrate. At low temperatures (say at around 0 centigrade) the rate of enzyme reaction is very slow. The molecules have low kinetic energy and collisions between them are less frequent and even if they do collide the molecules do not posses the minimum activation energy required for the reaction to occur. It can be said that the enzymes are deactivated at low temperatures. An increase in temperature increases the enzyme activity since the molecules now possess greater kinetic energy. The rate of enzyme activity is highest between 0-40 centigrade and this increase is almost linear. After 40 the rate of reaction starts to decrease. This is because the increase in temperature after 40 does not increase the kinetic energy of the enzyme but instead disrupts the forces maintaining the shape of the molecule. The enzyme molecules are gradually denatured causing the shape of the active site to change. Temperatures above 65 centigrade completely denature the enzymes. There are some enzymes known as ‘extremophiles’ found in thermophillic organisms. They retain activity at 80 centigrade. Test each separate temperature more than twice: This is to prove that each temperature is affecting the enzymes the same way each time and that the previous result was not...
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...Introduction Enzymes are protein molecules that catalyze chemical reactions in all living organisms. Enzymes allow living organisms to carry out complex chemical activities at low temperatures, but can’t cause a reaction that hasn’t occurred in their absence. Also, enzymes are thought to speed up reactions by bringing reacting molecules together to increase the chances that a reaction will occur (Worthington Biomedical Corporation, 2015). Each enzyme has a specific active site where the substrates attach. Many factors can affect enzyme activity such as temperature, pH, and the presence of inhibitors (John W. Kimball, 2014). The purpose of this lab was to examine factors affecting the enzyme function of peroxidase. In the 19th century French chemist Louis Jacques discovered catalysts. Catalysts are substances that enable a chemical reaction without participating in it, which led to specifically peroxidases. The structure of peroxidase is a very large enzymatic protein, and has complex molecules with complicated shapes involving multiple folding’s. The activity of peroxidase is dependent on pH. It exhibits maximum activity at a pH between 6.5 and 7.0. The activity of the enzyme is reduced when pH levels are increased. Peroxidase promotes the oxidation of various compounds naturally of peroxides, where hydrogen peroxide is reduced to form water (Wikimedia Foundation, 2015). Also peroxidases break compounds down into harmless substances by adding donor molecules. During this lab...
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...Enzymes Ally Wormaan 11/07/2013 Section 018 Introduction: Our body has many cells, cells which operate like a chemical factory. Chemicals are broken down for things like energy, and new chemicals are then synthesized. The food we eat only supplies us with some of the compounds that are needed for our body to operate. Most that are needed are synthesized within the cell by hundreds of different types of reactions that are all part of metabolism. All of these reactions wouldn’t be able to take place at body temperature. Or rather if they did, they would do so at a very slow rate. Enzymes are what allow the reactions to take place rapidly and efficiently. In this lab we will be demonstrating the role of enzymes as described, and also observing how the different concentration, temperature, pH, and inhibitors will affect the enzyme activity. Procedure: Prior to starting we will need to have three water baths readily available. One will be at 0-5*C, second at 35-40*c, and the last at boiling. The first part of this lab has us working with catalysis. We take three test tubes and add 2mL of 3%H2O2 to each. Test tube one will receive a small piece of raw liver. Test tube two receives a small piece of cooked liver, and test tube three does not receive anything. We will observe which solution quickly produces foam, and record our observations. We move onto enzyme concentrations. Again taking three test tubes we fill them as follows: Test tube # | 2% Rennin Solution mL | Distilled...
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...Introduction (5 marks) Enzymes are globular shaped proteins that are found throughout the body, with their main function being to act as biological catalysts. An enzyme can act to speed up or regulate the rate of the reaction, in order to maintain an efficient rate of biological reactions. Enzymes, whilst having an important role in the reaction of many chemicals within the body, are not consumed in the reaction, and so are able to catalyze many reactions in their life cycle. Enzymes are able to reduce the activation energy of the reaction; the energy required to break bonds between the reactants, and form new bonds in the products, which allows more product to be formed. (Marieb and Hoehn, 2010, pp.51-53). Enzyme activity is affected by changes in the pH of their solution. For each individual enzyme, there is a corresponding pH at which, that particular enzyme’s activity will be at it’s maximum. This is known as the optimum pH. If the pH of the solution is getting closer to it’s optimum pH for that particular enzyme, then the activity of the enzyme, and therefore it’s rate of reaction, will increase. At extremes of pH (either extremely acidic or basic) enzymes tend to become denatured; a state in which they lose all of their biological activity. (Worthington Biochemical Corporation, 2011). Temperature has the ability to increase the reaction rate of chemical reactions, by increasing the kinetic energy of the molecules themselves. By increasing the kinetic energy...
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...done by enzymes. If you understand enzymes, you understand cells. A bacterium like E. coli has about 1,000 different types of enzymes floating around in the cytoplasm at any given time. Enzymes have extremely interesting properties that make them little chemical-reaction machines. The purpose of an enzyme in a cell is to allow the cell to carry out chemical reactions very quickly. These reactions allow the cell to build things or take things apart as needed. This is how a cell grows and reproduces. At the most basic level, a cell is really a little bag full of chemical reactions that are made possible by enzymes! Enzymes are made from amino acids, and they are proteins. When an enzyme is formed, it is made by stringing together between 100 and 1,000 amino acids in a very specific and unique order. The chain of amino acids then folds into a unique shape. That shape allows the enzyme to carry out specific chemical reactions -- an enzyme acts as a very efficient catalyst for a specific chemical reaction. The enzyme speeds that reaction up tremendously. For example, the sugar maltose is made from two glucose molecules bonded together. The enzyme maltase is shaped in such a way that it can break the bond and free the two glucose pieces. The only thing maltase can do is break maltose molecules, but it can do that very rapidly and efficiently. Other types of enzymes can put atoms and molecules together. Breaking molecules apart and putting molecules together is what enzymes do, and...
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...Enzyme Regulatory Function Enzymes operate as catalysts by increasing and regulating all chemical reactions in a living organism within half the fraction of energy if they were not utilized. What makes enzymes so efficient and unique is that they can increase the rate of a reaction and alter chemical activity at the cellular level while still maintaining homeostasis and cellular equilibrium. In the absence of enzymes it would dramatically alter chemical reactions by decreasing the rate at which reactions occur and its by-products causing an increase demand for energy. When there is a defect in enzyme production it can severely alter how our bodies metabolize certain substances. Such as fructose, this is metabolized in the liver, and broken down by an enzyme called fructokinase. As fructose is broken down by fructokinase, it is converted to fructose 1-phosphate. The process continues as fructose 1-phosphate (f-1-p) is catalyzed by aldolase-B into DHAP-glyceraldehyde. The products generated by these reactions is formed into ATP, and used as cellular energy or when not needed, it is stored as glycogen in the liver for later use. If aldolase B were absent it would lead to a condition called, Hereditary Fructose Intolerance (HFI). HFI, an autosomal recessive disorder, occurs when aldolase-B does not function properly. Fructose 1-phosphate if not catalyzed by aldolase-B will cause a disruption in the cycle as the conversion of DHAP and glyceraldehydes are not produced; therefore...
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...Enzyme Experiment * Isolation of yeast invertase * Effect of temperature and pH Objectives * Determine the activity of an enzyme (invertase) * Determine the effects of pH and temperature in each activity Parts of the Experiment 1. Isolation 2. Sucrose Assay – to generate or construct a standard curve 3. Effect of temperature and pH a. Determine and graph the optimum pH and Temperature Enzymes will act on a compound or biomolecule (substrate, e.g. sucrose) to form a product Invertase + substrate equimolar concentration of fructose and glucose It will undergo hydrolosis – cleaves peptide bond or GLYCOCYLIC BOND OF SUCROSE Sucrose – carbohydrate -Disaccharide (composed of fructose and glucose) 2 ways in measuring enzyme activity 1. Measure the amount of product forms * Easier way * The more product formed, the more active enzyme 2. Substrate disappearance * The more substrate disappears, the more active invertase Purpose of Reagents 1. 0.05 mL of HCl - simulate the activity of enzyme - Hydrolyze the glycocylic bond 2. Heating to 90oC -ensures complete hydrolysis 3. 0.15mL of KOH - neutralize the solution 4. 2.80 mL buffer - retains same condition and optimum pH Sucrose assay using DNS 100mg/mL | Blank | 1 | 2 | 3 | 4 | 5 | 6 | mL std. sucrose | 0.00 | 0.25 | 0.50 | 0.75 | 1.00 | 1.25 | 1.50 | mL of water | 2.50 | 1.25 | 1.00 | 0.75...
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...Enzymes An enzyme is a protein molecule that helps to increase the rate in which chemical reactions occur. Recognizing an enzyme is very simple as they are named after a substrate with the suffix “ase” attached to the end. In terms of activation energy, an enzyme’s function is to decrease the amount of energy necessary for the reaction to take place. An enzyme inhibitor prevents that function from happening by binding to the enzyme. There are two different ways that enzyme inhibition can occur. The substrate imposter can either bind directly to the active site so the real substrate cannot bind or it can bind to a different site other than the active site. When it binds to another site it causes the enzyme to change its shape, therefore not allowing the real substrate to be accepted into the active site. Two different theories exist that explain how substrates fit into the active site of an enzyme. First is the Lock and Key theory which states that a substrate (key) fits into the active site of an enzyme (lock) perfectly without any change of shape of the active site at all, according to Elmhurst College’s virtual chemistry book. This theory differs from the Induced Fit theory, which states that when a substrate binds to the active site, the active site’s shape slightly changes to perfectly fit the substrate. Just like a protein, the class of macromolecule that an enzyme belongs to, the function of an enzyme depends greatly on its tertiary structure. If the structure of an...
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...Title: Enzyme Introduction The main reason for conducting this experiment is to establish the various factors that affect enzymes and reaction rates. Various experiments have been conducted to help gain a wide range of the factors that affect enzyme controlled reactions. Enzymes are affected by very many factors. It was the main aim of this experiment to establish these factors and the manner in which they affect them. This experiment also seeks to establish the manner in which some enzymes like Catalase affect the rates of reactions (Cohnheim 2009). Methods To establish the factors that affect enzymes, the procedures for the experiments to be carried out had to be almost perfect. For this reason the apparatus to be used had to be cleaned thoroughly just before commencing the experiment. To avoid differentiated results, similar kinds of apparatus were used all through the experiment. In this case glass test tubes were used. Also measuring apparatuses used were of the same size and volume. In this case four experiments were carried out. The first experiment is to establish the manner in which the enzyme Catalase affects reaction rates. The procedure of this experiment is as follows; using a pencil, label tree test tubes as test tube 1, 2 & 3. On these test tubes, label two marks using the pencil. These are at the 1cm mark and at the 5 cm mark. For the first test tube, pour in Catalase enzyme up to the first mark and add Hydrogen Peroxide up to the...
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...Enzymes and pH pH is a measure of H+ concentration. The higher the concentration of H+ the lower the pH values (acids) A hydrogen ion has a (+) charge so will be attracted to negatively charged molecules or parts of molecules. As like charges repel, positive molecules or parts of molecules will repel hydrogen ions. Large numbers of hydrogen bonds and ionic bonds are responsible for holding the tertiary structure of an enzyme protein in place. This ensures that the active site is also held in the right place. These bonds are due to the attraction between oppositely charged groups on the amino acids that make up the enzyme protein. Because of their charge, hydrogen ions can interfere with the hydrogen and ionic bonds in the molecule holding the tertiary structure in place. This means increasing or decreasing the concentration of hydrogen ions can alter the shape of the tertiary structure and therefore the shape of the active site. This can also aler the rate of an enzyme-controlled reaction. The induced-fit hypothesis suggests that an important part of catalysis in the active site relies on charged groups on the R-groups of the amino acids that make up the active site. Increasing the concentration of hydrogen bonds will alter the charges around the active site, as more hydrogen ions are attracted towards any negatively charged groups in the active site. Optimum pH At the optimum pH, the concentration of hydrogen ions in the solution gives the tertiary structure...
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...LAB REPORT: ENZYMES Part I: Graphs and Data TIME COURSE: ABSORBANCE VS. TIME Provided data: Time(minutes) | Experimental ABS @ 405nm | Control ABS @ 405 nm | Exp. ABS minus Control ABS | Micromoles p-Nitrophenol | 0 | 0.057 | 0.051 | 0.006 | 0.0004 | 10 | 0.207 | 0.053 | 0.154 | 0.0064 | 20 | 0.351 | 0.054 | 0.297 | 0.0120 | 30 | 0.501 | 0.055 | 0.446 | 0.0181 | 60 | 0.955 | 0.064 | 0.891 | 0.0362 | Personal data: Time(minutes) | Experimental ABS @ 405nm | Control ABS @ 405 nm | Exp. ABS minus Control ABS | Micromoles p-Nitrophenol | 0 | 0.092 | 0.064 | 0.028 | 0.0010 | 10 | 0.262 | 0.048 | 0.214 | 0.0085 | 20 | 0.429 | 0.054 | 0.375 | 0.0140 | 30 | 0.599 | 0.051 | 0.548 | 0.0208 | 60 | 0.976 | 0.050 | 0.926 | 0.0350 | STANDARD CURVE: Provided data: Micromoles p-Nitrophenol | Absorbance @ 405 nm | 0.0000 | 0.000 | 0.0025 | 0.058 | 0.0050 | 0.118 | 0.0100 | 0.245 | 0.0200 | 0.496 | 0.0400 | 1.000 | Personal data: Micromoles p-Nitrophenol | Absorbance @ 405 nm | 0.0000 | 0.000 | 0.0025 | 0.071 | 0.0050 | 0.167 | 0.0100 | 0.228 | 0.0200 | 0.519 | 0.0400 | 1.050 | TIME COURSE: PRODUCT VS. TIME Provided data: Time | Micromoles product | 0 | 0.0004 | 10 | 0.0064 | 20 | 0.0120 | 30 | 0.0181 | 60 | 0.0362 | Personal data: Time | Micromoles product | 0 | 0.0010 | 10 | 0.0085 | 20 | 0.0140 | 30 | 0.0208 | 60 | 0.0350 | TEMPERATURE: PRODUCT VS. TEMPERATURE Provided data: ...
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...Enzymes are proteins produced by a living organism, and act as efficient catalysts for specific chemical reactions. They are able to convert a specific set of reactants, known as substrates, into a specific set of products. Even at low temperatures, enzymes continue to allow a reaction to occur by lowering the activation energy of the given reaction. Reactions continue to occur even in the absence of enzymes, however due to the slow reaction rates without enzymes, sometimes the effects of the reaction would be considered insignificant. Enzymes are present in all aspects of plant metabolism, with their most important role in being the reduction of oxidative stress caused by photosynthesis and cellular respiration. These processes produce superoxide radicals, such as the anion O2-, which is a highly toxic by-product of metabolism within plant chloroplasts. The anion becomes no longer toxic with the use of the enzyme superoxide dismutase, which...
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