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The effects of the pH on enzyme activity
The Effects of Temperature on the Action of Enzymes
Investigation of the effects of temperature on enzyme-controlled reactions
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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.
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.
Just like the temperature, an enzyme can only work in a certain range of pH level. Different enzymes work in different pH levels. If, for example, if an enzyme that works in a pH level of one to three, as the pH level rises the enzyme begins ...
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...would be taking place more often and more oxidization of the enzyme by hydrogen peroxide as well.
Three drops of enzyme being added to the solution the enzyme activity would be higher than that of two drops or one drop of enzyme in the solution. The activity would be higher because there are more enzymes in the solution so there would be more movement of the enzymes in the solution because they would be bouncing off of each other. The structure of the enzyme would change because the oxidation process, a molecule losing an electron, therefore the function of the enzyme would change because the structure determines the function. So if the amount of enzyme increases or decreases, then the rate of enzyme activity will increase or decrease as well, meaning as the amount of enzyme goes up so will the activity, and if the amount of enzyme goes down so will the activity.
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
More hydrogen ions in a solution is a result of lower pH, while fewer hydrogen ions in a solution is a result of increased pH. Meaning that a lower pH level results in a higher enzyme activity reaction and a higher pH level results in a lower enzyme activity reaction (Christianson, 2011 ).
Overall, as the concentration of the substrate increases, the enzyme activity increases up to a 70% of solution, where the enzyme activity starts to level off. The curve is polynomial because of the fact that the enzyme activity exponentially increases as the concentration of substrate increase; additional evidence for this is the fact that the gradient graph is constantly changing. The polynomial curve is shown because until 70% (the saturation point); this is because there are more casein substrate molecules that can successfully collide with the renin enzyme molecule, therefore increasing the rate of reaction.
The alternate hypothesis is that there exists an optimal pH level for catecholase enzyme in which the catecholase enzyme can operate with the highest possible
Enzymes are biomolecules that catalyze or assist chemical reactions. ("Enzyme Information - Disabled World", n.d.,) Without enzymes it would be impossible for an organism to carry out chemical reactions. Enzymes are proteins that carry a chemical reaction for a specific substance or nutrient. For example, the digestive enzymes help food to be broken down so it can be absorbed. Enzymes can either initiate the reaction or speed it up. Substrates are the chemicals that are transformed by enzymes. (Gunsch & Foster, 2014) Reactants are the chemicals in the absence of enzymes. Metabolic pathways that occur in a cell are determined by a set of enzymes which are selective for their substrates and catalyze only a few reactions among the many possibilities.
Figure 3: The absorbance of peroxidase reactions over two minutes using pH 3, pH 5, pH 7, and pH 9.
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
needed to activate the reacting molecules. They are specific that usually act on only one type of substrate, so each of them just. perform one particular reaction. Furthermore, only a small amount of enzyme is needed every time to speed up a reaction. Enzymes are globular proteins that have a precise three-dimensional structure.
Enzymes are biological catalysts. They speed up the rate of a reaction without themselves being used up. Enzymes are individual proteins which controls a particular reaction or type of reaction. They are specific e.g. amylase always acts on starch.
Enzymes have the ability to act on a small group of chemically similar substances. Enzymes are very specific, in the sense that each enzyme is limited to interact with only one set of reactants; the reactants are referred to as substrates. Substrates of an enzyme are the chemicals altered by enzyme-catalysed reactions. The extreme specific nature of enzymes are because of the complicated three-dimensional shape, which is due to the particular way the amino acid chain of proteins folds.
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).
Enzymes work by lowering the activation energy required by molecules to start the reaction off. Enzymes also react (reversibly) with substrates (The molecule(s) that the enzyme is catalysing) this is done by forming Enzyme-substrate complex, which is then broken down into products. As well as being affected by temperature and pH enzymes optimum rate of reaction is also changed by competitive and non competitive inhibitors. Competitive inhibitors inhibit the enzyme so that enzyme-substrate complex’s cant form until it’s unblocked or there is a change in concentration in substrate, this means it takes longer to reach the optimum rate of 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.
The Effect of pH on Enzyme Activity. pH is a measure of the concentration of hydrogen ions in a solution. The higher the hydrogen ion concentration, the lower the pH. Most enzymes function efficiently over a narrow pH range. A change in pH above or below this range reduces the rate of enzyme reaction. considerably.
Enzymes are protein molecules that are made by organisms to catalyze reactions. Typically, enzymes speed up the rate of the reaction within cells. Enzymes are primarily important to living organisms because they help with metabolism and the digestive system. For example, enzymes can break larger molecules into smaller molecules to help the body absorb the smaller molecules faster. In addition, some enzyme molecules bind molecules together.