How Temperature Affects Enzyme Activity

Students will be observing normal catalase reaction, the effect of temperature on enzyme activity, and the effect of pH on enzyme activity in this experiment. The enzymes will all around perform better when exposed in room temperature than when it is exposed to hot and cold temperatures. This is based on the fact that the higher the temperature, the better the enzymes will perform, but as the temperature reaches a certain high degree, the enzymes will start to denature, or lose their function.

Hypothesis: I believe the rate of reaction will speed up as the temperature increases until it reaches about 37oC, which is the body temperature, where it will begin to slow down and stop reacting. I believe this will occur because enzymes have a temperature range at which they work best in and once the temperature goes out of this range the enzyme will stop working.

This experiment looked at how substrate concentration can affect enzyme activity. In this case the substrate was hydrogen peroxide and the enzyme was catalase. Pieces of meat providing the catalase were added to increasing concentrations of hydrogen peroxide in order to measure the effect of hydrogen peroxide concentrations on the enzyme’s activity. The variable measured was oxygen produced, as water would be too difficult to measure with basic equipment.

These results show how temperature of extreme high, or low affects enzyme activity. The highest rate of enzyme activity occurred at 37 Cº. Anything that was hotter or cold than 37 Cº slowed the reaction rate. As I thought, 100 degrees would denature the enzyme, and that was the case. The data provided shows exactly what temperatures enzymes work best, and worst. The objective was achieved as we discovered the different reaction rates under different temperatures. The results are reliable, as we know enzymes do not work well when under extreme heat or denaturation occurs. What I learned in this experiment was that enzymes don’t work well under cold temperatures because they tend to move slower. My hypothesis did not quite match, because I thought they work best at lower temperatures.

Most enzymes work best at body temperature, higher temps will cause the enzyme to no longer work properly

As stated in the introduction, three conditions that may affect enzyme activity are salinity, temperature, and pH. In experiment two, we explored how temperature can affect enzymatic activity. Since most enzymes function best at their optimum temperature or room temperature, it was expected that the best reaction is in this environment. The higher the temperature that faster the reaction unless the enzyme is denatured because it is too hot. Similarly, pH and salinity can affect enzyme activity.

Since enzymes are proteins, they are subject to denaturation at high temperatures. Catalase is an enzyme present in the human liver and functions at an optimum of 37°C. The data from the 36.7° C recording on table 1 proves this fact to be true. Any increase after 37°C will result in the denaturation of catalase, resulting in it becoming ineffective in the hydrolysis of hydrogen peroxide (“What is the Role of Catalase,” 2017). However, even after reaching boiling point a reaction, albeit small, still occurred. The reason for this reaction can be explained by the second law of thermodynamics. This law states that “during any process, the universe tends towards disorder [entropy]” (Carter Edwards et al, 2011). Living systems, are the exception to that law because they utilize energy in order to decrease entropy. In addition, the kinetic molecular theory of matter states that as temperature increases so does kinetic energy, or energy in motion (“The Kinetic Molecular Theory”). Thus, by increasing the kinetic energy of a reaction through an increase in temperature, the activation energy of a reaction will be decreased, and consequently the reaction rate will increase. So although the catalase may have been denatured, or almost fully denatured, a reaction was still possible due to the kinetic energy provided by the drastic increase in temperature.

The motive of this lab is to attain a better understanding of enzyme activity by timing chemical reactions in certain temperatures and pH levels. Enzymes act as catalysts that help speed up reactions. Without these enzymes chemical reactions in metabolism would be backed up. There are two factors that affect an enzyme’s reaction rate: temperature and pH levels. In this label we will be testing different pH levels and temperatures to see which ones cause the most reactions.

Abstract: Enzymes, catalytic proteins that at as catalysis which makes the process of chemical reactions more easily. There are two main factors that actually affects enzymes and their functions which are temperature and pH. Throughout this experiment, the study how pH and peroxidase affects each other and the enzyme was made. The recordings of how the enzymes responded when it was exposed to four different pH levels to come up with an optimum pH which was predicted in the hypothesis and the IRV at the end.

Introduction: Starting out with some background information, I know that enzymes are biological catalysts. The enzyme that I used for this experiment was potato juice. Enzymes make reaction rates go faster. They lower activation energy, making chemical reactions. Temperature has an effect on canola cultivars. The higher temperature decreased stem diameter, but room temperature had thicker stems. So I believe the same will happen for the catechol oxidase; the solution will react faster at room temperature. Other enzymes can also have different effects such as the enzyme in cattle serum. The enzyme lost activity in room temperature. With that being said room temperature can also be detrimental with specific enzymes. Fungus also

Five different temperatures of enzyme (spinach extract) (5°C, 20°C, 35°C, 45°C and 65°C) were added to individual measuring cylinders -each filled with 7ml of Hydrogen Peroxide (H202). The height of foam (oxygen + water) produced by the reaction was recorded for each temperature of the catalase after 30 seconds, to find at which degrees the enzyme activity had the fastest reaction rate. The data collected from this experiment suggested that the enzyme extract had the greatest efficiency at 20 °C, and the temperatures greater displayed a decline in rate of reaction.

The Effects of Varied Temperatures, pH Values, Enzyme Concentrations, and Substrate Concentrations on the Enzymatic Activity of Catecholase

Thermoregulation is important, especially in humans, as temperatures above 40 degrees Celsius cause enzymes to denature rapidly. Enzymes have an optimal range for catalysing reactions. Temperatures below this cause for the rate at which reactions occur to decrease, whereas temperatures above this can lead to the denaturing of enzymes and important metabolic reactions unable to occur. Therefore it is essential for enzymes in the body to be functioning.

There were three test tubes in which the experiment was held. A relatively equal sized portion of raw potato (this contained the enzyme [a biological catalyst] hydrogen peroxidase) was placed in each tube. Then, enough water to cover the potato was added. Proceeding this, each of the test tubes were assigned a temperature; cold, room temperature or warm (this was written on the tag so that they were not confused). The test tube destinated ‘cold’ was placed in a ice bath for five minutes. At the same time, the ‘hot’ test tube was placed in a hot water bath for five minutes. Meanwhile, the room temperature test tube sat at room temperature for five minutes. When the five minutes were over, the test tubes were returned to the rack (so that they were able to be observed). Then, the test tubes were allowed to sit at room temperature for five more minutes. Once that period of time was over, 2 ml of hydrogen peroxide (the substrate) was added to each tube.

To find the effect of temperature on the activity of an enzyme, the experiment deals with the steps as follows. First, 3 mL if pH 7 phosphate buffer was used to fill three different test tubes that were labeled 10, 24, and 50. These three test tubes were set in three different temperature settings. The first test tube was placed in an ice-water bath for ten minutes until it reached a temperature of 2° C or less. The second tube’s temperature setting was at room temperature until a temperature of 21°C was reached. The third tube was placed in a beaker of warm-water until the contents of the beaker reached a temperature setting of 60° C. There were four more test tubes that were included in the procedure. Two of the test tubes contained potato juice were one was put in ice and the other was placed in warm-water. The other two test tubes contained catechol. One test tube was put in ice and the other in warm water. After