Question

students investigated the activity of catalase, an enzyme that breaks down hydrogen peroxide, using samples of beef liver. in trial 1, hydrogen peroxide was poured on a piece of raw liver, and vigorous bubbling was observed. in trial 2, hydrogen peroxide was poured on a piece of liver that had been boiled for 5 minutes, and no bubbling occurred. what conclusion is best supported by these observations? a boiling the liver had no effect on catalase, so the reaction occurred normally. b boiling the liver destroyed the catalase enzyme, preventing hydrogen peroxide from breaking down. c boiling the liver caused hydrogen peroxide to evaporate before a reaction could take place. d boiling the liver turned hydrogen peroxide into oxygen directly, so no catalase was needed.

Explanation:

Enzymes like catalase are proteins. High - temperature (boiling) denatures proteins, changing their structure and function. In Trial 1, catalase in raw liver breaks down hydrogen peroxide causing bubbling. In Trial 2, boiling the liver denatures catalase, so hydrogen peroxide is not broken down and no bubbling occurs.

Answer:

B. Boiling the liver destroyed the catalase enzyme, preventing hydrogen peroxide from breaking down.