Aerobic respiration involves the transfer of many electrons from glucose to electron carriers such as NAD⁺ over a series of multiple steps.Ultimately though,it is the reaction of glucose with oxygen to generate carbon dioxide,water and energy.Why doesn't glucose react directly with oxygen in cells?

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The direct reaction of oxygen with glucose would release a large amount of energy all at once, which would be extremely destructive to cells. Instead, aerobic respiration allows for the controlled release of energy in multiple steps. Oxygen serves as the final electron acceptor in this process, but electron carriers like NAD+ and FADH2 are needed to transfer the electrons in a manageable fashion. Additionally, oxygen and glucose are not necessarily localized in different subcellular compartments, and oxygen can indeed accept electrons (which is why it is a crucial component of the electron transport chain). However, the reaction of oxygen with glucose is not spontaneous and requires the input of energy to overcome the activation energy barrier.

Aerobic Respiration Involves the Transfer of Many Electrons from Glucose