Outline7 marksChallenge
A student investigates two enzymes. Enzyme X is obtained from the lysosomes of a rat liver cell. Enzyme Y is obtained from the secretion of a pancreatic cell. The student measures the rate of reaction of each enzyme at a range of pH values. The results show that Enzyme X has an optimum pH of 5.0, while Enzyme Y has an optimum pH of 8.0.
Outline how the location of each enzyme (intracellular or extracellular) relates to its optimum pH and its role in the cell. In your answer, describe the general features of enzymes that allow them to function in these different environments, and explain the difference between the lock-and-key and induced-fit models of enzyme action.