Which of the following correctly lists the main stages of cellular respiration in the order they occur?

• A. Glycolysis, Electron transport chain, Krebs cycle
• B. Electron transport chain, Glycolysis, Krebs cycle
• C. Glycolysis, Krebs cycle, Electron transport chain
• D. Krebs cycle, Glycolysis, Electron transport chain

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the process of cellular respiration, which is the metabolic pathway cells use to convert glucose into energy in the form of ATP.
2. Step 2: Recall the three main stages of cellular respiration: Glycolysis, Krebs cycle (also known as the citric acid cycle), and the Electron Transport Chain (ETC).
3. Step 3: Glycolysis occurs first in the cytoplasm, where glucose is broken down into pyruvate, producing a small amount of ATP and NADH.
4. Step 4: The Krebs cycle follows, taking place in the mitochondrial matrix. Pyruvate is further broken down, generating more NADH, FADH2, and a small amount of ATP.
5. Step 5: The Electron Transport Chain is the final stage, occurring in the inner mitochondrial membrane. NADH and FADH2 donate electrons to the chain, driving the production of a large amount of ATP through oxidative phosphorylation.