Which process results in the transfer of energy from organic food to ATP?

Aerobic cellular respiration is the process that transfers energy from organic food molecules to ATP, the energy currency of the cell. This process involves several stages, including glycolysis, the Krebs cycle, and the electron transport chain. In glycolysis, glucose is broken down into pyruvate, producing a small amount of ATP and NADH. The pyruvate then enters the mitochondria, where it is further processed in the Krebs cycle, releasing electrons that are transferred through the electron transport chain. Here, the energy from these electrons is used to pump protons across the mitochondrial membrane, ultimately creating a proton gradient that drives the synthesis of ATP via ATP synthase.

This multi-step process is highly efficient, as it allows complete oxidation of glucose, generating up to 30-32 ATP molecules from a single glucose molecule. In contrast, fermentation only partially breaks down organic food and yields far less ATP, while photosynthesis is focused on converting light energy into chemical energy rather than transferring energy from food. Glycolysis is part of the overall aerobic cellular respiration process, but not the entire mechanism through which energy is transferred to ATP. Thus, aerobic cellular respiration is the most comprehensive answer describing the conversion of energy from organic food to ATP.