Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?

• A. Electron Transport Chain
• B. Glycolysis
• C. Oxidative Phosphorylation
• D. Citric Acid Cycle (Krebs Cycle)

Answer: (D)

Verified step by step guidance

1. Understand that cellular respiration is a multi-step process that converts glucose into ATP, the energy currency of the cell.
2. Identify the main stages of cellular respiration: Glycolysis, Citric Acid Cycle (Krebs Cycle), and Electron Transport Chain.
3. Recall that Glycolysis occurs in the cytoplasm and breaks down glucose into pyruvate, producing a small amount of ATP and NADH, but does not release CO2.
4. Recognize that the Citric Acid Cycle (Krebs Cycle) occurs in the mitochondria and involves the oxidation of acetyl-CoA, leading to the release of CO2 as a byproduct.
5. Note that the Electron Transport Chain and Oxidative Phosphorylation occur in the inner mitochondrial membrane, where ATP is produced, but CO2 is not released in these stages.