Carbohydrates are broken down into glucose monomer and dimers. Glucose is conver
ID: 90871 • Letter: C
Question
Carbohydrates are broken down into glucose monomer and dimers. Glucose is converted to pyruvate and then to acetyl CoA. Acetyl CoA enters the citric acid cycle and is broken down to CO2 and in the process produces NADH & FADH2, which is utilized in the generation of ATP via the electron transport chain. Why does the cell go through this elaborate pathway to convert glucose to carbon dioxide and water and in the process generate ATP? Why not use a simpler and shorter mechanism to breakdown glucose?
Explanation / Answer
This is because citric acid cycle(Kreb's cycle) is the most efficient way for breakdown of glucose which gives maximum amount of ATPs. The total ATPs produced after using up NADH & FADH2 is 24 compared to a simpler process of glycolysis which produces 8 ATPs. Glycolysis also consumes 2 molecules of ATP while Kreb's cycle don't. The intermediates and products of the Kreb's cycle are used up in certain other processes of the body while glycolysis produces lactic acid which may be harmful for the body.