Question

Answer the following question

1. Does the amount of enzyme influence the rate of reaction ?

2. Does the temperature of the solution influence activity of enzyme ?

3. Boiling an enzyme before a reaction does not influence its activity. ( is this correct and why ?)

4. The pH of the solution does not influence the activity of an enzyme ( is this correct and why?)

Answer 1

1. With the increase in the enzyme concentration, the rate of the reaction increases linearly because there are more enzyme molecules available to catalyze the reaction. At very high enzyme concentration, the substrate concentration may become rate-limiting, so the rate stops increasing.

2. Chemical reactions are influenced by temperature. At low temperatures, reactions slow down because the molecules have less energy. As the temperature increases, the rate of a reaction increases as well. SImilar thing happens with enzymes.

3. This statement is incorrect. An enzyme is a protein molecule with a fixed 3-D shape that is held in place by ionic bonds, hydrogen bonds. Due to boiling these bonds will be broken and tertiary structure of the enzyme will be lost and it will not be able to form an enzyme-substrate complex to form products. The active site will lose its complementary shape and the enzyme will be denatured. However, some enzymes are resistant to very high temperatures.

4. This statement is incorrect. Changes in pH affect the shape of an enzyme and also change the shape or charge properties of the substrate so that either the substrate cannot bind to the active site or it cannot undergo catalysis.