Final answer:
The step between glycolysis and the Krebs cycle involves pyruvate decarboxylation, not the electron transport chain or oxidative phosphorylation, which occur later in cellular respiration.
Step-by-step explanation:
The step between glycolysis and the Krebs cycle involves the transformation of pyruvate into acetyl-CoA. This step is known as the transition reaction or pyruvate decarboxylation, where an acetyl group is attached to coenzyme A and NADH is formed. This acetyl-CoA then enters the Krebs cycle (also called the citric acid cycle), where it goes through a series of reactions to generate additional NADH and FADH2, as well as ATP through substrate-level phosphorylation. However, the electron transport chain and oxidative phosphorylation are not involved in the step between glycolysis and the Krebs cycle.
They are part of the later stages of cellular respiration, where the NADH and FADH2 produced in the Krebs cycle donate electrons to generate a large amount of ATP.