How is carbon dioxide produced in aerobic respiration?

Carbon dioxide is produced in aerobic respiration during the process of the Krebs cycle in the mitochondria.

Aerobic respiration is a metabolic process that occurs in the mitochondria of cells. It involves the breakdown of glucose in the presence of oxygen to produce energy, water, and carbon dioxide. The process consists of three main stages: glycolysis, the Krebs cycle, and the electron transport chain.

Glycolysis, which occurs in the cytoplasm, is the first stage of aerobic respiration. It involves the breakdown of one molecule of glucose into two molecules of pyruvate. This process does not produce carbon dioxide.

The Krebs cycle, also known as the citric acid cycle, is the second stage of aerobic respiration and it occurs in the mitochondria. Here, the pyruvate molecules produced in glycolysis are further broken down. Each pyruvate molecule is converted into Acetyl CoA, which then enters the Krebs cycle. During this cycle, the Acetyl CoA is oxidised to produce carbon dioxide, ATP (adenosine triphosphate), NADH and FADH2. The carbon dioxide produced is a waste product and is expelled from the body through the lungs.

The final stage is the electron transport chain, which also takes place in the mitochondria. The NADH and FADH2 produced in the Krebs cycle donate their electrons to the electron transport chain. This process does not produce carbon dioxide.

In summary, carbon dioxide is produced in aerobic respiration during the Krebs cycle when Acetyl CoA is oxidised. This carbon dioxide is then expelled from the body as a waste product.