Question

What is the net yield of ATP molecules produced during the glycolysis of one glucose molecule?

• A. 2 ATP
• B. 4 ATP
• C. 6 ATP
• D. 8 ATP

Hint:

Glycolysis → Invest 2 ATP, produce 4 ATP → Net gain = 2 ATP.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Glycolysis is the metabolic pathway that breaks down glucose into pyruvate, releasing energy in the form of ATP.
Step 2: Key Formula or Approach:
Net ATP = (Gross ATP produced) $-$ (ATP consumed during activation).
Step 2: Detailed Explanation:
Glycolysis consists of two main phases:
1. Energy-Investment Phase: 2 ATP molecules are consumed to activate glucose (phosphorylate it).
2. Energy-Payoff Phase: 4 ATP molecules are produced via substrate-level phosphorylation (2 per three-carbon unit).
Calculation: \[ 4 \text{ ATP (produced)} - 2 \text{ ATP (invested)} = 2 \text{ ATP (net)} \]
Although NADH is also produced (which can yield more ATP in the Electron Transport Chain), the "net yield" of glycolysis refers specifically to the direct ATP output.
Step 3: Final Answer:
The net yield of ATP from one molecule of glucose during glycolysis is 2 ATP.