Question

Briefly explain the process of cellular respiration in eukaryotes.

Answer 1

Cellular respiration in eukaryotes involves following steps:

1) Glycolysis occurs in cytosol and is oxygen-independent (anaerobic). It results in breakdown of glucose into two molecules of pyruvate. It generates ATP by substrate level phosphorylation and NADH which is transferred to mitochondria for ATP synthesis via oxidative phosphorylation.

2) Oxidative decarboxylation of pyruvate occurs in mitochondrial matrix under aerobic conditions to generate acetyl-CoA.

3) Krebs Cycle or citric acid cycle or TCA cycle occurs in mitochondrial matrix under aerobic conditions to generate ATP/GTP by substrate level phosphorylation and NADH/FADH2 that are used as reducing equivalents during oxidative phosphorylation to generate ATP.

4) Electron Transport Chain, present in inner mitochondrial membrane, facilitates oxidative phosphorylation under aerobic conditions. It uses oxygen as terminal electron acceptor during ATP formation.