Sun28November0333PM 30

Adenosine-5-triphosphate (ATP) is used in cells as a coenzyme and is an energy source.

Which one of the following biochemical processes produces the most ATP from the metabolism of glucose?

(Please select 1 option)

Anaerobic respiration in the cytoplasm

Electron transport phosphorylation in the mitochondria Correct

Glycolysis in the cytoplasm

Oxidation of pyruvate to acetyl CoA in the mitochondria

Krebs cycle in the mitochondria

Explanation

Glycolysis occurs in the cytoplasm and converts 1 glucose molecule (6-carbon) to pyruvate (two 3-carbon molecules). It produces 4 ATP molecules and 2NADH but uses 2 ATP in the process. The net energy production is 2 ATP.

Pyruvate is then oxidised to acetyl coenzyme A (generating 2 NADH per pyruvate molecule), which then enters the Krebs cycle (citric acid cycle). This takes place in the mitochondria and produces 2 ATP, 8 NADH and 2 FADH2 per glucose molecule.

The aim of electron transport phosphorylation is to break down NADH and FADH2 and pump H+ into the outer compartment of the mitochondria. This process occurs in the mitochondria.

Electron transport phosphorylation typically produces 32 ATP. Net energy production is 36 ATP.

Anaerobic respiration occurs in the cytoplasm and pyruvate is reduced to NAD producing 2 ATP.

Answer Statistics

1

1%

2

51%

3

2%

4

11%

5

38%

Times answered: 245