Final answer:
At the end of glycolysis, about 90-95 percent of the energy is still contained within the chemical bonds of the pyruvate molecules. While some ATP is produced, most energy is held for subsequent stages of cellular respiration.
Step-by-step explanation:
At the end of glycolysis, about 90-95 percent of the chemical energy is locked in the bonds of the pyruvate molecule. Glycolysis begins with a glucose molecule, which undergoes a series of reactions. The process is split into two phases: the energy-investment phase and the energy-payoff phase. During the investment phase, two ATP molecules are consumed to phosphorylate glucose, which prepares the six-carbon sugar molecule for cleavage into two three-carbon molecules. In the payoff phase, energy is extracted and four ATP molecules are produced, but the majority of the energy originally present in glucose remains in the pyruvate molecules that are formed at the end of glycolysis. This energy is further harvested in later stages of cellular respiration.