Question

question 7 of 25
a dog paddles across a lake. what would happen to the dog if the hydrogen
ion pumps in its mitochondria stopped functioning?
a. the dog would start using anaerobic respiration.
b. the dog would gain more energy from glycolysis.
c. the dog would not have any energy left for activity.
d. the dog would gain a large amount of energy.

Explanation:

Mitochondria are the powerhouses of the cell. Hydrogen ion pumps in mitochondria are crucial for oxidative phosphorylation, which generates a large amount of ATP (energy currency of the cell). If these pumps stop functioning, the electron transport chain (which relies on hydrogen ion gradients created by these pumps) cannot produce ATP efficiently. Glycolysis (which occurs in the cytoplasm) only produces a small amount of ATP (2 ATP per glucose molecule) compared to oxidative phosphorylation (around 30 - 32 ATP per glucose molecule). Anaerobic respiration (like lactic acid fermentation in animals) also produces very little ATP and is not sustainable for long - term, energy - demanding activities like paddling across a lake. So, without functional hydrogen ion pumps in mitochondria, the dog would not have enough energy (ATP) for the activity of paddling.

Answer:

C. The dog would not have any energy left for activity.