Here's a breakdown of the process:
1. Glycolysis:
* Glucose is broken down into two pyruvate molecules, yielding a net gain of 2 ATP and 2 NADH.
2. Pyruvate Oxidation:
* Pyruvate is converted into acetyl-CoA, producing 1 NADH per pyruvate molecule.
3. Citric Acid Cycle (Krebs Cycle):
* Acetyl-CoA enters the citric acid cycle, generating 3 NADH, 1 FADH2, and 1 ATP per acetyl-CoA molecule.
4. Oxidative Phosphorylation:
* The electron carriers NADH and FADH2 donate electrons to the electron transport chain, driving proton pumping across the inner mitochondrial membrane. This creates a proton gradient that is used by ATP synthase to produce ATP.
ATP Yield:
* Glycolysis: 2 ATP
* Krebs Cycle (per glucose molecule): 2 ATP
* Oxidative Phosphorylation: 32 ATP (from NADH and FADH2)
Total: 36 ATP
Important Note: This theoretical yield of 36 ATP is a maximum value. The actual ATP yield varies depending on factors such as:
* The efficiency of proton pumping in the electron transport chain
* The use of ATP for other cellular processes
* The shuttle systems used to transport electrons into the mitochondria
Therefore, the typical range of ATP produced from a single glucose molecule is closer to 29-32 ATP.
