Question

After the citric acid cycle is complete, where is most of the energy from the reactants?

a) in the electron carriers, NADH and FADH2
b) in molecules of pyruvate
c) in a proton gradient
d) lost as heat
e) still in glucose

Answer 1

Most of the energy from the reactants after the citric acid cycle is stored in the electron carriers NADH and FADH2, which are later used in the electron transport chain to produce ATP.

Step-by-step explanation:

After the citric acid cycle is complete, most of the energy from the reactants is in the electron carriers, NADH and FADH2. During the citric acid cycle, each acetyl group entering the cycle is turned into carbon dioxide, water, and high-energy electron carriers. The electron carriers are crucial as they transport energy to the electron transport chain, where most ATP is generated during oxidative phosphorylation. It’s during this stage that the proton gradient is established for ATP synthesis.