Questions: Which statement is correct about the Krebs cycle? In the Krebs cycle, carbon dioxide is used to make glucose. Oxygen is a waste product of the Krebs cycle. Acetyl-CoA combines with pyruvic acid to make glucose in the Krebs cycle. The Krebs cycle produces electron carriers for the electron transport chain.

Which statement is correct about the Krebs cycle? Analyze the provided image and recall the key features of the Krebs cycle. The image shows that the Krebs cycle takes place in the mitochondrion and produces electron carriers (NADH and FADH2) that are used in the electron transport chain. The Krebs cycle also produces a small amount of ATP. The starting material for the Krebs cycle is pyruvate, which is converted to Acetyl-CoA before entering the cycle. The cycle itself involves a series of reactions that ultimately regenerate the starting molecule, allowing the cycle to continue. CO2 is released as a waste product during the Krebs cycle. Evaluate each of the given statements.

• _In the Krebs cycle, carbon dioxide is used to make glucose._ This is incorrect. Carbon dioxide is a waste product of the Krebs cycle, not a reactant.
• _Oxygen is a waste product of the Krebs cycle._ This is incorrect. While oxygen is the final electron acceptor in the electron transport chain, it is not directly involved in the Krebs cycle. CO2 is the waste product of the Krebs cycle.
• _Acetyl-CoA combines with pyruvic acid to make glucose in the Krebs cycle._ This is incorrect. Pyruvate is converted to acetyl-CoA _before_ entering the Krebs cycle. The Krebs cycle breaks down acetyl-CoA, not builds glucose.
• _The Krebs cycle produces electron carriers for the electron transport chain._ This is correct. The Krebs cycle produces NADH and FADH2, which carry electrons to the electron transport chain. \(\boxed{\text{The Krebs cycle produces electron carriers for the electron transport chain.}}\)

\(\boxed{\text{The Krebs cycle produces electron carriers for the electron transport chain.}}\)