Question

There are 38 molecules of ATP produced in aerobic respiration and how many are formed outside the mitochondria?
A)2
B)20
C)4
D)14

Answer 1

Hint: Cellular respiration is a series of biochemical reactions and processes that take place in the cells of organisms to turn chemical energy into adenosine triphosphate (ATP) from oxygen molecules or nutrients and then to release waste products. Catabolic reactions that break large molecules into smaller ones, releasing energy when weak high-energy bonds, particularly in molecular oxygen, are substituted by stronger bonds in products, are the reactions involved in respiration.

Complete answer:
Chemical energy contained in ATP (it is possible to break the bond of the third phosphate group to the rest of the molecule, allowing more stable products to form and thereby releasing energy for cell use) will then be used to drive energy-intensive processes, including biosynthesis, locomotion or molecular transport through cell membranes.
Aerobic cellular respiration is a gradual process which, like heat, avoids energy loss.

The degradation of glucose into two pyruvate molecules is glycolysis; it occurs outside the mitochondria, producing 2 ATP molecules.
Enzymes for the Krebs cycle are found in the mitochondria's fluid-filled matrix. Pyruvate thus diffuses into mitochondria and is converted into acetyl CoA to join the cycle of citric acid.
36 ATP molecules are formed during the citric acid cycle. There are 38 ATP molecules produced in aerobic respiration all together, and 2 ATPs are formed outside the mitochondria.

Hence, the correct answer is option (A)

Note: For the use of glucose energy, fermentation is less efficient: only 2 ATP per glucose is produced, as opposed to 38 ATP per glucose nominally produced by aerobic respiration. This is because, with its comparatively thin, high-energy double bond, much of the strength of aerobic respiration comes from $O_2$ . However, glycolytic ATP is produced faster.