Question

Which of the following is/are true about the Krebs Citric Acid cycle?

I. It occurs in the matrix and inner membrane of the mitochondria.
II. There are 8 steps in total.
III. It involves both anabolic and catabolic reactions.

O I, II, and III
O II, and III
O II only
O I and II

Answer 1

The Krebs Citric Acid Cycle occurs in the mitochondrial matrix and consists of eight enzymatic steps that involve both anabolic and catabolic processes. The inner mitochondrial membrane is relevant for the electron transport chain but not the cycle itself.

Step-by-step explanation:

Krebs Citric Acid Cycle Details:

The Krebs Citric Acid cycle, a key component of cellular respiration, consists of a series of eight enzymatic steps that occur within the mitochondrial matrix. These reactions are both anabolic and catabolic, as they involve the synthesis and breakdown of complex molecules. It is here where the two-carbon compound acetyl CoA is fully oxidized to carbon dioxide. During this cycle, NADH and FADH₂ are produced, which carry electrons to the electron transport chain located at the inner mitochondrial membrane.

Regarding the given statements, we can confirm that:

• The Krebs cycle occurs in the matrix of the mitochondria, which excludes the inner membrane where the electron transport chain is located.
• Correct, there are eight steps in the Krebs cycle.
• The cycle involves both anabolic and catabolic reactions since molecules are both built up and broken down to harness energy.

Therefore, the correct answer is I and III: