Final answer:
The process of glycolysis is initiated by (Option a) ATP, which phosphorylates glucose, and during the pathway, two ATP molecules are ultimately generated. Glucose is split into two pyruvate molecules, and the potential energy in glucose is used to generate ATP and NADH.
Step-by-step explanation:
The process of glycolysis is kickstarted by the investment of energy in the form of ATP. Initially, ATP is required to phosphorylate glucose, which is the first step of glycolysis. Specifically, one molecule of ATP is used to convert glucose into glucose-6-phosphate, which is a necessary step to trap glucose within the cell and to continue the glycolytic pathway.
During glycolysis, the six-carbon glucose molecule is eventually split into two three-carbon molecules of pyruvate. Later in the process, energy is generated when ADP is phosphorylated to ATP, which happens twice per molecule of glucose, hence yielding a net gain of two ATP molecules. This transformation is part of the energy payoff phase of glycolysis. Additionally, energy is released when ATP is hydrolyzed to ADP and a phosphate group, and this reaction releases energy from the breaking of the phosphodiester bonds between phosphate groups.
In terms of potential energy, glucose is likely to have the most potential energy as it is the initial molecule that is catabolized into ATP, NADH, and pyruvate during glycolysis and further metabolized in the Krebs cycle and oxidative phosphorylation.