Question

In prokaryotes, aerobic respiration generates ________ ATP molecules.

A) 2
B) 15
C) 38
D) 42
E) 0

Answer 1

In prokaryotic aerobic respiration, one glucose molecule theoretically yields up to 38 ATP molecules, with 34 from oxidative phosphorylation and 4 from substrate-level phosphorylation, making option C) 38 the correct answer.

Step-by-step explanation:

In prokaryotes, the complete aerobic respiration of one glucose molecule theoretically yields up to 38 ATP molecules. This total includes 4 ATPs produced from substrate-level phosphorylation during glycolysis and the Krebs cycle and an additional 34 ATPs from oxidative phosphorylation via the electron transport chain (ETC). It is important to note that under aerobic conditions, NADH contributes to the formation of approximately 3 ATPs per molecule, while FADH₂ contributes to about 2 ATPs per molecule. However, variations exist between different species of prokaryotes due to differences in the efficiency of their electron transport systems.

In eukaryotic cells, some energy is used to transport cellular intermediates into the mitochondria which can reduce the total yield of ATP. Despite this, 36-38 ATP molecules are generally accepted as the net ATP produced during aerobic respiration of one molecule of glucose in prokaryotic cells. Hence, the correct answer to the question is C) 38.