How many ATP molecules are re-synthesised during anaerobic glycolysis according to the material?

How many ATP molecules are re-synthesised during anaerobic glycolysis according to the material?

• A. 1
• B. 2
• C. 3
• D. 4

Answer: (B)

The key idea is the amount of ATP you actually gain from glycolysis when oxygen isn’t present. In anaerobic glycolysis, you start by spending 2 ATP to activate glucose. Later, you harvest 4 ATP from substrate-level phosphorylation as the pathway runs to pyruvate. The net result is 2 ATP produced per glucose. In the absence of oxygen, pyruvate is converted to lactate to regenerate NAD+, which keeps glycolysis going but doesn’t add extra ATP beyond that net 2. So the best answer is 2 ATP re-synthesised per glucose under anaerobic conditions.

The key idea is the amount of ATP you actually gain from glycolysis when oxygen isn’t present. In anaerobic glycolysis, you start by spending 2 ATP to activate glucose. Later, you harvest 4 ATP from substrate-level phosphorylation as the pathway runs to pyruvate. The net result is 2 ATP produced per glucose. In the absence of oxygen, pyruvate is converted to lactate to regenerate NAD+, which keeps glycolysis going but doesn’t add extra ATP beyond that net 2. So the best answer is 2 ATP re-synthesised per glucose under anaerobic conditions.