Factors that affect Enzyme activity Essay Example

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The rate of reaction depends on the concentration of enzymes. When the enzyme concentration is low, there is a fierce competition for active sites, leading to a slower reaction rate. However, as the enzyme concentration increases, more active sites become available and the reaction proceeds faster due to increased collisions between enzymes and substrates. Eventually, increasing the enzyme concentration no longer affects the reaction rate because the substrate concentration becomes the limiting factor. Thus, it can be inferred that initially increasing enzyme concentration enhances the reaction rate until it becomes limited by substrate availability. Experimental data would likely show a graph depicting this pattern: an increase in reaction rate with increasing enzyme concentration followed by a plateau when substrate availability becomes limiting.

The rate of reaction is influenced by the concentration of substrate. When there is a low concentration of substrate, there are not enough molecules to interact with the active sites of enzymes, resulting in a slow reaction rate and limited reactions. However, increasing the substrate concentration will enhance the rate of reaction as more substrate molecules collide with enzyme molecules and lead to increased product formation. Nonetheless, once a certain concentration threshold is met, further increases in substrate concentration will no longer impact the rate of reaction. This is because the enzymes become saturated at this point and operate at their maximum capacity. If we were to investigate this factor, we would expect that as substrate concentration rises until saturation occurs, so does the rate of reaction. The accompanying graph demonstrates this anticipated relationship.

The proposed image below depicts the relationship between enzyme and substrate concentration, which is discussed in the factors affecting

enzyme activity. It is referred to as the "picture of proposed investigation below".

Temperature plays a crucial role in enzyme activity. Each enzyme has an optimal temperature that allows it to achieve the highest reaction rate for a specific reaction. In the human body, most enzymes function optimally at 37 degrees Celsius, which is the internal temperature of the body. This is because enzymes like catalase have adapted to work best at this temperature.

When the temperature is below the optimum, substrates have low kinetic energy and fewer of them enter the active site for catalysis. However, as the temperature increases towards the optimum, both substrates and enzymes gain more kinetic energy and collide more frequently, leading to a chemical reaction.

As the temperature exceeds the optimum, the bonds holding enzymes together also gain kinetic energy and vibrate at a higher speed.This results in the disruption of chemical bonds within the enzyme, causing a change in its shape. As a result, the active site's altered shape becomes less compatible with the substrate's shape, reducing its ability to facilitate reactions. Ultimately, this leads to denaturation of the enzyme and loss of functionality. Additionally, as temperature increases, there is a decrease in the number of active sites available on enzyme molecules for binding substrate molecules. Consequently, this further contributes to enzyme denaturation and lowers the reaction rate. It can be inferred that the reaction rate reaches its peak at 37 degrees Celsius – known as the optimum temperature for catalase activity. Any deviation from this optimal temperature will result in a decline in reaction rate, as explained in the subsequent paragraph. Therefore, it is reasonable to anticipate that my collected

data will resemble the graph displayed below:

The pH level measures the acidity and basicity of a solution, indicating the concentration of hydrogen ions (H+) and hydroxide ions (OH-). It can range from pH1 to pH14, with lower values indicating higher H+ concentrations and lower OH- concentrations.

Contrary to enzymes in the human body that have the same optimum temperature of 37°C, enzymes have varying optimum pH values. For instance, pepsin functions best at a pH of 2.0 while catalase has an optimum pH of 7.6. The location of enzymes affects their optimum pH values due to differences in environmental conditions. Pepsin is most efficient at pH 2 because it is commonly found in the stomach, which has a low pH caused by hydrochloric acid. Enzymes have a specific pH range in which they work effectively, and any deviation from the optimum pH will result in a sudden decrease in the rate of reaction as the active sites of more enzyme molecules become less complementary to their substrates.

Small changes above or below the optimum do not permanently change enzymes, as the bonds can be reformed. However, extreme pH changes can cause enzymes to denature and lose their function permanently. When pH deviates from the optimal level for a specific enzyme, H+ and OH- ions interfere with the hydrogen and ionic bonds that hold the enzyme together. These ions are attracted to or repelled by the charges created by the bonds, leading to a change in the enzyme's shape, particularly its active site. I would anticipate a decrease in enzyme activity as pH deviates from 7.8, the optimum for catalase. This is because

the active site becomes less compatible for substrate binding and eventually becomes denatured. The accompanying graph supports my expectation, which I anticipate my data will reflect.

Out of all the possible factors, I have chosen to research temperature.