Pepsin, a peptidase that hydrolyzes proteins, functions in the stomach at an optimum pH of 1.5 to 2.0.
Which of the following would cause an increase in its activity?

Pepsin, an enzyme that hydrolyzes peptide bonds in proteins, functions in the stomach at a pH optimum of 1.5 to 2.0. How is the rate of a pepsin-catalyzed reaction affected by each of the following conditions?

c. running the reaction at 0 °C

Problems 10.94 and 10.95 both mention enzymes that hydrolyze peptide bonds. How do you account for the fact that pepsin has a high catalytic activity at pH 1.5 but chymotrypsin has very little activity at pH 1.5?

Meats spoil due to the action of enzymes that degrade the proteins. Fresh meats can be preserved for long periods of time by freezing them. Explain how freezing meats works to prevent spoilage.

Adults who are lactose intolerant cannot break down the disaccharide in milk products. To help digest dairy food, a product known as Lactaid can be given prior to consuming dairy products. (16.4, 16.5)

b. What might happen to the enzyme if the Lactaid were stored at 55 °C?

Sucrase has an optimum pH range of 4.5 – 7.0. Which of the following statements is true?

What do we mean when we say an enzyme is saturated with substrate? When an enzyme is saturated with substrate, how does adding more (a) substrate and (b) enzyme affect the rate of the reaction?

How do you explain the observation that pepsin, a digestive enzyme found in the stomach, has a high catalytic activity at pH 1.5, while trypsin, an enzyme of the small intestine, has no activity at pH 1.5?

What general effects would you expect the following changes to have on the rate of an enzyme-catalyzed reaction for an enzyme that has its maximum activity at body temperature (about 37°C)?

a. Raising the temperature from 37°C to 70°C