Question

question 22 of 25
which best describes consumption of glucose in the krebs cycle?
a. the krebs cycle runs four times for each molecule of glucose consumed.
b. the krebs cycle consumes one molecule of glucose in each cycle.
c. the krebs cycle consumes two molecules of glucose in each cycle.
d. the krebs cycle runs twice for each molecule of glucose consumed.

Explanation:

Glucose is first broken down into two pyruvate molecules during glycolysis. Each pyruvate is then converted into acetyl - CoA. Since the Krebs cycle processes one acetyl - CoA per cycle, and there are two acetyl - CoA molecules from one glucose molecule (via glycolysis and pyruvate oxidation), the Krebs cycle runs twice per glucose molecule. Options A, B, and C are incorrect as they do not match the stoichiometry of glucose breakdown and Krebs cycle input.

Answer:

D. The Krebs cycle runs twice for each molecule of glucose consumed.