Question

Why did the scientist not use glucose as the respiratory substrate for the isolated mitochondria when investigating the effect of the enzyme inhibitor malonate on the succinate to fumarate reaction?

A) Glucose is too expensive.
B) Glucose is toxic to mitochondria.
C) Glucose cannot be used by mitochondria.
D) Glucose is a substrate for glycolysis, not the Krebs cycle.

Answer 1

The scientist did not use glucose as the respiratory substrate for the isolated mitochondria because it is a substrate for glycolysis, not the Krebs cycle.

Step-by-step explanation:

The scientist did not use glucose as the respiratory substrate for the isolated mitochondria because glucose is a substrate for glycolysis, not the Krebs cycle.

Mitochondria utilize glucose in the process of glycolysis, which breaks down glucose into pyruvate to generate ATP. However, in the investigation of the effect of malonate on the succinate to fumarate reaction, the focus is on the Krebs cycle, where succinate is converted to fumarate.

The isolated mitochondria were specifically used to study the enzymes and reactions involved in the Krebs cycle. Since glucose is not directly involved in the Krebs cycle, it was not used as the respiratory substrate.