All living cells require ATP to function; (read details for full question its too long)?

Question

Some cells produce 36 ATP per glucose molecule oxidized. Others produce only 2 ATP per glucose. Why such a DIFFERENCE if all living cells require ATP to function?

Answer 1

The ones producing up to 36-38 ATP per glucose molecule are performing Aerobic Cellular Respiration. This involves a long series of reactions, an electron transport chain, and oxygen. Without oxygen there is no aerobic respiration.

Those that produce 2 ATP per glucose are performing anaerobic cellular respiration or fermentation. This occurs in the absence of oxygen. Because there is such a small amount of ATP made, this is mainly used by simple life forms as a means of survival. Complex life forms use this method as a back-up to aerobic respiration.

Answer 2

The difference has to do with whether the cells are relying primarily on the glycolytic pathway (2ATP) or they are going all the way and carrying out oxidative respiration which creates much more ATP per glucose molecule. Yeast, under conditions of high oxygen environment (aerobic) will metabolize glucose by oxidative respiration. When there is not enough oxygen present for O2 to be used as an electron acceptor oxidative respiration cannot occur and the yeast will rely exclusively on the less efficient glycolytic pathway to produce ATP.

Answer 3

First, the high end ATP producers require oxygen and that is a serious limitation, especially when you consider that the oxygen levels needed to run such a process are a relatively recent circumstance in geological terms.

So, without a dependence on oxygen, the lower-producing cells can find niches many more places.

Additionally, high levels of cellular complexity and size are often supported by and allowed by the higher levels of ATP production. This level of complexity also comes with other costs and risks.

The lower production cells, generally simpler, are able to reproduce and often adapt to environmental changes more quickly simply because of a short time between generations.

Answer 4

smaller goes through glycolysis, other through oxidative phosphorylation