Which of the following molecules act as electron carriers in aerobic cellular respiration?

In aerobic cellular respiration, the primary electron carriers are NADH and FADH2. Both of these molecules play crucial roles in the processes of glycolysis, the citric acid cycle, and the electron transport chain.

NADH is generated during glycolysis and the citric acid cycle when glucose is broken down. It carries electrons to the electron transport chain, where it donates them to lead to the production of ATP through oxidative phosphorylation. FADH2 is also produced in the citric acid cycle and serves a similar purpose, transferring electrons to the electron transport chain, albeit at a different site compared to NADH, which affects the amount of ATP generated from each carrier.

While ATP is essential for energy transfer within the cell, it does not function as an electron carrier. Similarly, although oxygen is critical as the final electron acceptor in the electron transport chain, and glucose serves as the initial source of fuel in cellular respiration, neither acts as an electron carrier in the same way as NADH and FADH2 do.