Question

How are the TCA and ETC related?

Answer 1

TCA and ETC:

1. TCA is tricarboxylic acid and ETC is an electron transport chain.
2. The TCA cycle is the second stage of cellular respiration, with the first stage being glycolysis.
3. It is also known as the citric acid cycle and Krebs cycle.
4. ETC is the last stage in cellular respiration.
5. In a series of enzymatic reactions, the TCA cycle generates the FADH²⁺ and NADH²⁺, which are needed to transfer electrons to the mitochondrial respiratory chain.
6. As the electrons are funneled through the complexes present in the inner mitochondrial membrane, a functional ETC generates a mitochondrial membrane potential, which is used to produce ATP.
7. This process needs the presence of oxygen and is known as oxidative phosphorylation.
8. Mitochondrial complex I and II in the ETC replenish NAD⁺ and FAD respectively, permitting the oxidative TCA cycle to function.
9. Succinate dehydrogenase is the only enzyme, which participates in both the ETC and TCA cycles.
10. TCA cycle is the major energy-yielding metabolic pathway in cells.