Calculation of molecules of last electron acceptor in ETS
- Number of ATP molecules produced from one molecule of isocitrate in aerobic respiration:
- Isocitrate undergoes several steps in the Krebs cycle to produce ATP through oxidative phosphorylation.
- Each molecule of isocitrate produces 3 molecules of NADH, 1 molecule of FADH2, and 1 molecule of GTP.
- These electron carriers (NADH and FADH2) donate electrons to the electron transport chain (ETC) for ATP synthesis.
- Role of electron transport chain (ETC) in ATP synthesis:
- The ETC is a series of protein complexes located in the inner mitochondrial membrane.
- Electrons from NADH and FADH2 are passed through the ETC, leading to the pumping of protons across the membrane.
- The final electron acceptor in the ETC is oxygen, which combines with protons to form water.
- Number of molecules of last electron acceptor (oxygen) required:
- For each molecule of NADH passing through the ETC, 3 molecules of ATP are produced.
- For FADH2, 2 molecules of ATP are produced.
- Therefore, for one molecule of isocitrate (producing 3 NADH and 1 FADH2), a total of 10 molecules of ATP are produced.
- Since 1 molecule of oxygen is required to accept electrons in the ETC, the number of oxygen molecules needed is 1.
In conclusion, when one molecule of isocitrate is used as a substrate during aerobic respiration, the number of molecules of the last electron acceptor (oxygen) required in the ETC is 1.