Wait a second!
More handpicked essays just for you.
More handpicked essays just for you.
Catalytic activity of enzymes lab report
Catalytic activity of enzymes lab report
How are the rates of enzyme reactions affected by temperature
Don’t take our word for it - see why 10 million students trust us with their essay needs.
Recommended: Catalytic activity of enzymes lab report
Lab Report on Measuring the Rate of Conversion of Hydrogen Peroxide using Enzyme Catalysis In essence, the main objective was to use chemical titration to measure and then calculate the rate of conversion of hydrogen peroxide (H2O2) to water and oxygen by using the enzyme catalase. Other purposes of the lab were; to measure the effects of changes of temperature, pH, enzymes concentration, and substrate concentration on rates of an enzyme. The lab was also an opportunity to see a catalyzed reaction in a controlled experiment. And the last objective was to learn how environmental factors affect the rate of enzyme catalyzed reactions. Enzymes are proteins produced by living cells. They act as catalysts in biochemical reactions. A catalyst speeds up the rate of a chemical reaction and makes it possible for the reaction to occur with a lower initial input of energy. One benefit of enzyme catalysis is that the cell can carry out complex chemical activities at a relatively low temperature (AP Lab Manual). In biochemical reactions, the enzyme, E, combines reversibly with its specific substrate, S, to form a complex ES. One result of this temporary formation is a reduction in the energy required to activate the reaction of the substrate molecule so that P, the products of the reaction are formed. In summary: E+SESE+P. The enzyme is not changed in the reaction and can break down additional substrate molecules (Lab Bench). The enzyme used in this lab is catalase. Catalase has a molecular weight of approximately 240,000 daltons and contains four polypeptide chains, each composed of more than 500 amino acids. This enzyme occurs universally in aerobic organisms. One function of catalase within cells is to prevent the accu... ... middle of paper ... ...n activator, or if it decreases the reaction rate it is an inhibitor. These molecules can regulate how fast the enzymes act. Any substance that tends to unfold the enzyme, such as an organic solvent or detergent, will act as an inhibitor. Some inhibitors act by reducing the -S-S- bridges that stabilize the enzyme's structure. Many inhibitors act by reacting with the side chains in or near the active site to change its shape or block it. Many well known poisons such as potassium-cyanide and curare are enzyme inhibitors that interfere with the active site of critical enzymes (Enzyme Catalysis). Bibliography: References: "Enzyme Catalysis" sc2000.net. 1page. 21, Feb. 2002 "Lab Bench: Enzyme Catalysis" Biology.com. Pg. 1-3. 21, Feb. 2002 http://www.biology.com/learning/enzyme/concepts.html AP biology lab manual (appropriate reference and date N/A)
For example, substrate concentration, enzyme concentration, and temperature could all be factors that affected the chemical reactions in our experiment. The concentration of substrate, in this case, would not have an affect on how the bovine liver catalase and the yeast would react. The reason why is because in both instances, the substrate (hydrogen peroxide) concentration was 1.5%. Therefore, the hydrogen peroxide would saturate the enzyme and produce the maximum rate of the chemical reaction. The other factor that could affect the rate of reaction is enzyme concentration. Evidently, higher concentrations of catalase in the bovine liver produced faster reactions, and the opposite occurs for lower concentrations of catalase. More enzymes in the catalase solution would collide with the hydrogen peroxide substrate. However, the yeast would react slower than the 400 U/mL solution, but faster than the 40 U/mL. Based on this evidence, I would conclude that the yeast has a higher enzyme concentration than 40 U/mL, but lower than 400
Catalase is a common enzyme that is produced in all living organisms. All living organisms are made up of cells and within the cells, enzymes function to increase the rate of chemical reactions. Enzymes function to create the same reactions using a lower amount of energy. The reactions of catalase play an important role to life, for example, it breaks down hydrogen peroxide into oxygen and water. Our group developed an experiment to test the rate of reaction of catalase in whole carrots and pinto beans with various concentrations of hydrogen peroxide. Almost all enzymes are proteins and proteins are made up of amino acids. The areas within an enzyme speed up the chemical reactions which are known as the active sites, and are also where the
Enzymes are proteins that increase the speed of reactions in cells. They are catalysts in these reactions which means that they increase the speed of the reaction without being consumed or changed during the reactions. Cofactors are required by some enzymes to be able to carry out their reactions by obtaining the correct shape to bind to the other molecules of the reaction. Chelating agents are compounds that can disrupt enzyme reactions by binding to metallic ions and change the shape of an enzyme. Catechol is an organic molecule present under the surface of plants. When plants are injured, catechol is exposed to oxygen and benzoquinone is released because of the oxidation of catechol. Catecholase aids in the reaction to produce
That means the active site and the substrate should be exactly complementary so that the substrate can fit in perfectly. Once they collide, the substrate and. some of the side-chains of the enzyme’s amino acids form a temporary. bond so that the substrate can be held in the active site. They combine to form an enzyme-substrate complex and the enzyme can start.
== == == = This is what I'm going to be changing in the experiment and this will be the temperature and the concentration of the yeast. There are several variables in this experiment, they are: · Amount Used - Too much or too little of the hydrogen peroxide causes the reaction to speed up/slow down producing different amounts of oxygen.
Introduction / Background Information. This is an experiment to examine how the concentration of the substrate Hydrogen Peroxide (H2O2) affects the rate of reaction of the enzyme Catalase. In this experiment I will be using yeast as a source of catalase. Enzymes are catalysts which speed up specific reactions. Enzymes such as catalase are protein molecules, which speed up a specific reaction within the cell.
The three-dimensional contour limits the number of substrates that can possibly react to only those substrates that can specifically fit the enzyme surface. Enzymes have an active site, which is the specific indent caused by the amino acid on the surface that fold inwards. The active site only allows a substrate of the exact unique shape to fit; this is where the substance combines to form an enzyme- substrate complex. Forming an enzyme-substrate complex makes it possible for substrate molecules to combine to form a product. In this experiment, the product is maltose.
Enzymes are proteins or RNA, ribonucleic acid. An enzyme speeds up a chemical reaction. Since the enzyme is not changed by speeding up a chemical reaction, the enzyme can speed up reactions again and again. In a process called catalysis, an enzyme takes what would have been a relatively slow reaction, and makes it faster than the reaction would have been without the enzyme. Enzymes also take the activation energy, which is the energy needed to start reactions, and shortens it. With the decrease in the amount of activation energy needed, reactions could occur more often, and less energy would be needed to begin each reaction. When an enzyme takes a substrate, which is a specific reactant, it changes the substrate in a specific way (Unity and Diversity 82). The active site on the enzyme is a specific shape, so the enzyme can only change certain substrates, the ones that fit into the enzyme’s activation site like a piece in a puzzle.
The results of this experiment showed a specific pattern. As the temperature increased, the absorbance recorded by the spectrophotometer increased indicating that the activity of peroxidase enzyme has increased.At 4C the absorbance was low indicating a low peroxidase activity or reaction rate. At 23C the absorbance increased indicating an increase in peroxidase activity. At 32C the absorbance reached its maximum indicating that peroxidase activity reached its highest value and so 32 C could be considered as the optimum temperature of peroxidase enzyme. Yet as the temperature increased up to 60C, the absorbance decreased greatly indicating that peroxidase activity has decreased. This happened because at low temperature such as 4 C the kinetic energy of both enzyme and substrate molecules was low so they moved very slowly, collided less frequently and formed less enzyme-substrate complexes and so little or no products. Yet, at 23 C, as the temperature increased, enzyme and substrate molecules
= == In relative terms enzymes are biological catalysts; control the rate of chemical reaction, different temperatures and pH’s affect their optimum rate of reaction in living organisms. In detail; enzymes are globular proteins, which catalyse chemical reactions in living organisms, they are produced by living cells – each cell has hundreds of enzymes. Cells can never run out of enzymes as they or used up in a reaction.
In this lab, it was determined how the rate of an enzyme-catalyzed reaction is affected by physical factors such as enzyme concentration, temperature, and substrate concentration affect. The question of what factors influence enzyme activity can be answered by the results of peroxidase activity and its relation to temperature and whether or not hydroxylamine causes a reaction change with enzyme activity. An enzyme is a protein produced by a living organism that serves as a biological catalyst. A catalyst is a substance that speeds up the rate of a chemical reaction and does so by lowering the activation energy of a reaction. With that energy reactants are brought together so that products can be formed.
Jim Clark. (2007). The effect of changing conditions in enzyme catalysis. Retrieved on March 6, 2001, from http://www.chemguide.co.uk/organicprops/aminoacids/enzymes2.html
Enzymes are types of proteins that work as a substance to help speed up a chemical reaction (Madar & Windelspecht, 104). There are three factors that help enzyme activity increase in speed. The three factors that speed up the activity of enzymes are concentration, an increase in temperature, and a preferred pH environment. Whether or not the reaction continues to move forward is not up to the enzyme, instead the reaction is dependent on a reaction’s free energy. These enzymatic reactions have reactants referred to as substrates. Enzymes do much more than create substrates; enzymes actually work with the substrate in a reaction (Madar &Windelspecht, 106). For reactions in a cell it is important that a specific enzyme is present during the process. For example, lactase must be able to collaborate with lactose in order to break it down (Madar & Windelspecht, 105).
Without enzymes, reactions wouldn’t occur and living organisms would die. For instance, the enzyme in the stomach breaks down large molecules to smaller molecules to absorb nutrition faster. Researchers experimented with enzyme activity with a potato extract. Researchers will test enzyme activity by increasing and decreasing pH levels, lowering and increasing temperature, and substrate concentration effects. In the first experiment, researchers hypothesized whether different pH levels would change how much Benzoquinone are created and how will the enzymes function in neutral pH levels than higher and lower levels. Researchers used potato extract and different levels of pH to test their hypothesis. In addition, researchers questioned at what temperature does the greatest amount of potato extract enzyme activity take place in. Researchers then hypothesized that the results would indicate the greatest amount of potato enzyme activity level will take place in room temperature. In this experiment, researchers used potato extract and different temperature levels to test the hypothesis. Moreover, researchers wanted to test the color intensity scale and how specific catechol oxidase is for catechol. In this experiment, researchers used dH2O, catechol solution, hydroquinone, and potato extract. Lastly, researchers tested the substrate concentration and how it has an effect on enzyme activity. In this experiment researchers used different measurements of catechol and 1cm of potato extract. Researchers hypothesized that the increase o substrate would level out the enzyme activity
The temperature of the water shows if the temperature in which catalase reacts in has an effect on the amount of oxygen produced. Every enzyme has an optimum amount of pH, which allows it to have a higher reaction velocity (WBC).The higher the reaction velocity the more reactive the enzyme is. Measuring the different amount of pH solutions and their effect on the amount of oxygen produced can show the optimum pH for catalase and the effect pH has on catalase. The data that these three independent variables will yield will allow us to better understand the effects concentration, temperature and pH have on the enzyme catalase. If catalase reacts at full concentration, 37 degrees celsius and a pH of eight the enzyme catalase will produce more oxygen than if it is at room temperature, a lower concentration and a more acidic base because the higher temperature will allow molecules to move faster and have a higher chance to collide and react, a higher concentration will create a higher enzyme to substrate ratio which allows it to react more and finally a more basic pH will allow it catalase to have a higher reaction