Question

How would anaerobic conditions (when no O2 is present) affect the rate of electron transport and ATP production during oxidative phosphorylation? (Note that you should not consider the effect on ATP synthesis in glycolysis or the citric acid cycle.)
a) Electron transport would be unaffected but ATP synthesis would stop.
b) Electron transport would stop but ATP synthesis would be unaffected.
c) Both electron transport and ATP synthesis would stop.
d) Neither electron transport nor ATP synthesis would be affected.

Answer 1

Answer:

c) Both electron transport and ATP synthesis would stop.

Explanation:

We need oxygen to survive. Absence of oxygen can make can lead to one's death. This is because we need oxygen so that our cells can use it during oxidative phosphorylation, the last stage of cellular respiration. Oxygen is found at the end of the electron transport chain, where it accepts electrons and picks up protons to form water. Absence of oxygen at this stage will make the electron transport chain to stop running, and ATP will not be produced.

Answer 2

Answer:

The answer is a) electron transport would be unaffected but ATP synthesis would stop.

Explanation:

In absence on oxygen cells would undergo either lactic or alcohol fermentation. During this process the electron transport will facilitate the regeneration of NAD+ from the NADH produced during glycolysis. In this way, the cycle can be repeated. The ATP production in the absence of oxygen is equal to the molecules generated during glycolysis: 2 molecules per one molecule of glucose.