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Enzymes and their importance in animals
The effects of temperature on enzyme activity
The effects of temperature on enzyme activity
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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. In this experiment hydrogen peroxide
was used as the substrate, which is the substance on which an enzyme acts. The binding between enzymes and substrates consists of weak, non-covalent chemical bonds, forming a complex that lasts for a very short amount of time (Freeman 28). During this limited amount of time, the covalent bonds of the hydrogen peroxide will be stressed or are positioned in a certain way that facilitates the development of different molecules. From this, comes the formation of products. The product exits the enzyme’s active sight and is then used by the cell. The reaction does not affect the enzyme and can begin the catalytic cycle again if there are an abundance of molecules. The pH and high salt concentrations interfere with ionic bonds, which affects the shape of enzyme molecules. This, in turn, affects the ability of a substrate to bind efficiently to the enzyme. Temperature, affects the frequency leading to the collision of the substrate and enzyme, which affect it’s binding (Starr 102). Extremely high temperatures will usually cause enzyme denaturation, making an inactive enzyme. All factors that influence binding will affect the rate of enzyme-catalyzed reactions. During this particular experiment, the enzyme, peroxidase will be used. Which is a large protein that has an iron ion in its active site, acting as a cofactor. In the lab, a peroxidase reaction will occur and the observing of the production of an oxidized product will monitor its activity. The dye, guaiacol binds to peroxidase and becomes oxidized as the hydrogen peroxide is eventually reduced to water. To measure the amount of brown color in the final product, the enzyme and substrates were mixed and then measured in a spectrophotometer. As color accumulates, the absorbance at 500nm will increase. After conducting two experiments it will be observed that peroxidase is necessary for oxygen using cells. How competitive inhibitors impact enzyme activity, why peroxidase is a necessary enzyme for all oxygen-using cells, and how the rate of enzyme-catalyzed reaction is affected by physical factors. It is hypothesized that changes in temperature have an effect on enzyme activity. Also, it is hypothesized that hydroxylamine causes reaction change with enzyme activity. The predictions for these two experiments was that peroxidase activation will be shorter with an increase in temperature and that since hydroxylamine has a similar molecular structure to hydrogen peroxide the enzyme activity must be similar as well.
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
Living organisms undergo chemical reactions with the help of unique proteins known as enzymes. Enzymes significantly assist in these processes by accelerating the rate of reaction in order to maintain life in the organism. Without enzymes, an organism would not be able to survive as long, because its chemical reactions would be too slow to prolong life. The properties and functions of enzymes during chemical reactions can help analyze the activity of the specific enzyme catalase, which can be found in bovine liver and yeast. Our hypothesis regarding enzyme activity is that the aspects of biology and environmental factors contribute to the different enzyme activities between bovine liver and yeast.
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
The affects of pH, temperature, and salt concentration on the enzyme lactase were all expected to have an effect on enzymatic activity, compared to an untreated 25oC control. The reactions incubated at 37oC were hypothesized to increase the enzymatic activity, because it is normal human body temperature. This hypothesis was supported by the results. The reaction incubated to 60oC was expected to decrease the enzymatic activity, because it is much higher than normal body temperature, however this hypothesis was not supported. When incubated to 0oC, the reaction rate was hypothesized to decrease, and according to the results the hypothesis was supported. Both in low and high pH, the reaction rate was hypothesized to decrease, which was also supported by the results. Lastly, the reaction rate was hypothesized to decrease in a higher salt concentration, which was also supported by the results.
When the flame was blown out and the glowing wooden splint was placed halfway into the test tube containing H2O2 and MnO2 crystals, the splint reignited and caught flame once again. This demonstrates the decomposition of H2O2 into water and hydrogen. MnO2 is a catalyst that increases the rate at which H2O2 decomposes. Adding oxygen to a fire will cause it to burn faster and hotter and the oxygen rich test tube allowed the splint to reignite.
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
This graph shows that as enzyme concentration increases absorption also increases. In this case absorbance can be used to measure the enzyme’s activity, the higher the absorption the higher the activity. Since absorption increases as enzyme concentration increases, enzyme activity is promoted by increased enzyme concentrations. After a certain point enzyme activity would fail to increase as a result of increased enzyme concentration since there wouldn’t be enough substrate for all of the enzymes to react with.
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
Background information:. Enzyme Enzymes are protein molecules that act as the biological catalysts. A Catalyst is a molecule which can speed up chemical reactions but remains unchanged at the end of the reaction. Enzymes catalyze most of the metabolic reactions that take place within a living organism. They speed up the metabolic reactions by lowering the amount of energy.
According to the graph on amylase activity at various enzyme concentration (graph 1), the increase of enzyme dilution results in a slower decrease of amylose percentage. Looking at the graph, the amylose percentage decreases at a fast rate with the undiluted enzyme. However, the enzyme dilution with a concentration of 1:3 decreased at a slow rate over time. Additionally, the higher the enzyme dilution, the higher the amylose percentage. For example, in the graph it can be seen that the enzyme dilution with a 1:9 concentration increased over time. However, there is a drastic increase after four minutes, but this is most likely a result of the error that was encountered during the experiment. The undiluted enzyme and the enzyme dilution had a low amylose percentage because there was high enzyme activity. Also, there was an increase in amylose percentage with the enzyme dilution with a 1: 9 concentrations because there was low enzyme activity.
= == 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.
There are several things that can affect the function of an enzyme: the temperature, pH level, and salinity of the environment. The temperature affects an enzyme by increasing the molecular motion by increasing the amount of free energy that is available. The more free energy that there is, the reaction is closer to its activation energy (Unity and Diversity 83). The enzyme can only work in a certain temperature range, and if the temperature gets too high, the enzyme denatures, loses its shape, and therefore its function because its shape determines the function.
In our Biology Lab we did a laboratory experiment on fermentation, alcohol fermentation to be exact. Alcohol fermentation is a type of fermentation that produces the alcohol ethanol and CO2. In the experiment we estimated the rate of alcohol fermentation by measuring the rate of CO2 production. Both glycolysis and fermentation consist of a series of chemical reactions, each of which is catalyzed by a specific enzyme. Two of the tables substituted some of the solution glucose for two different types of solutions. They are as followed, Table #5 substituted glucose for sucrose and Table #6 substituted the glucose for pH4. The equation for alcohol fermentation consists of 6 Carbons 12 Hydrogens 6 Oxygen to produce 2 pyruvates plus 2 ATP then finally the final reaction will be 2 CO2 plus Ethanol. In the class our controlled numbers were at Table #1; their table had 15 mL Glucose, 10 mL RO water, and 10 mL of yeast which then they placed in an incubator at 37 degrees Celsius. We each then measured our own table’s fermentation flasks every 15 mins for an hour to compare to Table #1’s controlled numbers. At
Enzymes are necessary for life to exist the way it does. Enzymes help our bodies carry out chemical reactions at the correct speed. Catalase is one such enzyme, “Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals). It catalyzes the decomposition of hydrogen peroxide to water and oxygen”.\(Wikipedia). In other words catalase speeds up the breaking down of hydrogen peroxide, which is a byproduct of reactions in our body. Hydrogen peroxide is very common in our body but, “If it were allowed to build up it would kill us”(Matthey).This shows how necessary enzymes such as catalase to life. Without enzymes reactions that take place in our body could be affected greatly. In our
All biological processes require a constant supply of energy. The fabrication and regulation of energy is a result of catalytic reactions that occur in cells by enzymes. Enzymes typically contain a few active sites that enable substrates (reactants) to bind to their designated enzyme and form an enzyme-substrate complex, to then release the product (Alberte J. , Pitzer T. , Calero K.). In order for an enzyme to release a product, the reactant molecules must absorb enough energy from their surroundings to reach the unstable transition state and form new bonds at a faster rate without the denaturization of the enzyme. Enzymes have sets of conditions at which they are enabled to work properly, known as the optimal condition. For experiment 4,