ATP molecules, which are used for energy by cells, are built during all three stages of cellular respiration. Which stage of cellular respiration generates the most ATP molecules

The Electron transport chain of the cellular respiration generates the most ATP molecules.

Explanation:

The cellular respiration takes place in three phases: glycolysis, Kreb's cycle and Electron transport.

In glycolysis net gain of 2 ATP occurs, Kreb cycle 2 GTPs, ETC 32 ATPs

In Kreb's cycle 2 GTP, 6 NADH, two FADH2 is formed. These are used in the electron transport chain to produce ATP by redox and oxidation reactions.

Each NADH produces 3 ATPs

each FADH2 produces 2 ATP

GTP=ATP