Factors That Affect Enzyme Reaction Rate

Lab Report Factors That Affect Enzymes Reaction Rate Name of lab: Effects of temperature, pH, Enzyme Concentration, and Substrate Concentration on Enzymatic Activity Introduction: Enzymes are the most important types of proteins, they act as catalysis (speed up chemical reactions). If enzymes didn’t exist, biochemical reactions would act to slowly and they couldn’t keep up with the metabolic functions. Enzymes have a three-dimensional structure that is really complex. This structure consists of one or more polypeptide chains, they form an active site, which is an area in which the substrate eventually will fit.

The four factors that affect the activity and reaction rate of an enzyme are temperature, pH, enzyme concentration and substrate concentration. Research Question/Hypothesis: The hypothesis is that when the temperature is higher than 40? C, the enzyme catalysis will increase. That the enzyme activity with the pH effect is that if it isn’t at the optimum pH value there will be a total loss of the enzyme activity. As the change in enzyme concentration increases the activity rate will increase if there is a proportional amount of enzyme concentration and substrate.

Variables: Independent: pH, enzyme concentration, substrate concentration and enzymatic activity. Dependent: the reaction rate Control variable: temperature and amount of substrates and enzymes added. Materials: Phosphate Buffers Beaker Catechol Potato Juice Parafilm Test Tubes Procedure: To study the effect of temperature: 1. Three different test tubes where filled with 3mL of phosphate. 2. They were set in three different temperature settings. First tube was placed in an ice-water bath for ten minutes, the second in a room temperature until 21?

C was reached, and the third tube was placed in a beaker of warm water. To study the effect of pH: 1. The pH values of pH 4, pH 6, pH 7, pH 8, and pH 10 was used to fill five separate test tubes with 3 mL each. 2. To each test tube, ten drops of catechol and potato juice were added, each tube was covered with Parafilm, and inverted several times to mix the contents. After letting each tube stand for three to five minutes the tubes were inverted at one minute intervals. To study the effect of enzyme concentration: 1.

The steps include four test tubes that were labeled A, B, C, and D. 2. The contents added to tube A are 3mL plus 20 drops of pH 7 phosphate buffer, but no potato juice. To tube B, 3 mL plus 15 drops of pH 7 phosphate buffer and 15 drops of potato juice. The amount of pH 7 phosphate buffer added to test tube C are 3 mL plus 10 drops of potato juice. To test tube D, 3 mL of pH 7 phosphate buffer and 20 drops of potato juice were added. 3. Then, each tube was covered in Parafilm and inverted several times to mix the contents.

After doing so, 10 drops of catechol were added to each tube and covered with Parafilm and inverted several times to mix the contents. 4. After allowing each tube to stand for three to four minutes the tubes were mixed at one-minute intervals. To study the effects of substrate concentration: 1. Eight test tubes that were involved. 2. These test tubes were labeled 1, 2, 4, 8, 16, 24, 32, and 48. Next, each test tube had a certain amount of phosphate buffer and catechol was added to each. 3.

To test tube #1: 5 mL plus 47 drops of pH 7 phosphate buffer and 1 drop of catechol; test tube #2: 5 mL plus 46 drops of pH 7 phosphate buffer and 3 drops of catechol; test tube #4: 5 mL plus 44 drops of pH 7 phosphate buffer and 4 drops of catechol; test tube #8: 5 mL plus 40 drops of pH 7 phosphate buffer and 8 drops of catechol; test tube #16: 5 mL plus 32 drops of pH 7 phosphate buffer and 16 drops of catechol; test tube #24: 5 mL plus 24 drops of pH 7 phosphate buffer and 24 drops of catechol; test tube #32: 5 Ml plus 16 drops of pH 7 phosphate buffer and 32 drops of catechol; and test tube #48: 5 mL of pH 7 phosphate buffer and 48 drops of catechol. 4. Then, each tube was covered with Parafilm and inverted several times to mix the contents. Also, to each of the tubes, 30 drops of potato juice were added and covered with Parafilm and inverted several times to mix the contents. The test tubes set at room temperature for five minutes and were mixed at one minute intervals.