What is Krebs cycle and what is its role in aerobic respiration

Krebs cycle is a series of reactions that take place in the mitochondria of most living cells and result in the production of energy during aerobic respiration. During Krebs cycle oxygen is metabolised to produce carbon dioxide and water as waste products and ADP is converted to ATP which is the enrgy currency of the cell

During Krebs cycle, citrate (six-carbon melecule mae of oxaloacetate and acetyl CoA) is gradually broken down to reform oxaloacetate (four-carbon acceptor molecule)

To summarize

Two molecules of CO2 are produced

One molecule of ATP is formed

Three molecules of NAD+ are combined with hydrogen (NAD+ → NADH)

One molecule of FAD combines with hydrogen (FAD → FADH₂)

Since two acetyl-CoA molecules are produced from each glucose molecule, two cycles are required per glucose molecule. Therefore, at the end of two cycles, the products are: two ATP, six NADH₂, two FADH₂ two QH₂ (ubiquinol) and four CO₂.