Question

Some explanations of glycolysis, lactic acid fermentation and aerobic cellular respiration seem to indicate that your cells SWITCH between the two options to finish glycolysis: lactic acid fermentation OR cellular respiration. This is not the case! Your cells do not choose EITHER lactic acid fermentation OR aerobic cellular respiration.

Therefore, a better explanation might be: “If a cell is only getting 75% as much O2 as it needs to make enough ATP through aerobic cellular respiration, then (what %?) of the pyruvates from glycolysis will go into the mitochondria.”

Answer 1

Ans. -

Fermentation occurs in absence of oxygen means anaerobic respiration. Aerobic respiration means in presence of oxygen.

Pyruvate oxidation is the step that connects glycolysis and the Krebs cycle. In glycolysis, a single glucose molecule (6 carbons) is split into 2 pyruvates (3 carbons each), hence link reaction occurs twice for each glucose molecule to produce a total of 2 acetyl-CoA molecules, which can then enter the Krebs cycle.

In absence of oxygen link reaction Will not occur thus, no Krebs cycle & no ETS.