How much ATP does 1 glucose molecule make?

How much ATP does 1 glucose molecule make?

• A. 36 ATP
• B. 40 ATP
• C. 2 ATP
• D. 4 ATP

Answer: (A)

In aerobic respiration, the energy from one glucose molecule is captured across several stages, with the electron transport chain doing most of the work. The total ATP yield is commonly taught as about 36 ATP per glucose, though the exact number can vary depending on how the electrons from cytosolic NADH are shuttled into the mitochondria and how many ATP are assigned to each NADH and FADH2. Glycolysis makes a modest amount directly (a couple of ATP) and also generates NADH. Pyruvate oxidation and the citric acid cycle produce NADH and FADH2, which feed the electron transport chain. Each NADH and FADH2 ultimately helps synthesize ATP as protons are pumped across the inner membrane and ATP synthase converts ADP to ATP. When you tally the ATP produced directly and those generated via the chain from all stages, the sum comes out to about 36 ATP in the common teaching model. Differences in reported numbers (such as 30–32 or 38) arise from different assumptions about the ATP yield per NADH and per FADH2 and the particular shuttle systems used to move electrons from glycolysis into mitochondria. The 36 ATP figure reflects a standard, widely used estimate for educational purposes.

In aerobic respiration, the energy from one glucose molecule is captured across several stages, with the electron transport chain doing most of the work. The total ATP yield is commonly taught as about 36 ATP per glucose, though the exact number can vary depending on how the electrons from cytosolic NADH are shuttled into the mitochondria and how many ATP are assigned to each NADH and FADH2.

Glycolysis makes a modest amount directly (a couple of ATP) and also generates NADH. Pyruvate oxidation and the citric acid cycle produce NADH and FADH2, which feed the electron transport chain. Each NADH and FADH2 ultimately helps synthesize ATP as protons are pumped across the inner membrane and ATP synthase converts ADP to ATP. When you tally the ATP produced directly and those generated via the chain from all stages, the sum comes out to about 36 ATP in the common teaching model. Differences in reported numbers (such as 30–32 or 38) arise from different assumptions about the ATP yield per NADH and per FADH2 and the particular shuttle systems used to move electrons from glycolysis into mitochondria. The 36 ATP figure reflects a standard, widely used estimate for educational purposes.