Final answer:
Glycolysis begins with phosphorylation of glucose by hexokinase using one ATP molecule, which starts the process of glucose oxidation.
Step-by-step explanation:
The process that starts the oxidation of glucose in glycolysis is the phosphorylation of glucose by the enzyme hexokinase. This is where the first ATP molecule is used to add a phosphate group to glucose, forming glucose-6-phosphate. As glycolysis continues, energy is consumed in phase 1 (also known as the "Priming Step") and later on, energy is captured in ATP and NADH in phase 2. The formation of NADH occurs when high-energy electrons are extracted from glyceraldehyde-3-phosphate, which is then oxidized and phosphorylated.