Final answer:
Glycolysis begins with the phosphorylation of glucose by hexokinase to form glucose-6-phosphate, followed by the conversion to fructose-6-phosphate. The process involves the donation of phosphate groups from ATP and the splitting of a six-carbon sugar into two three-carbon molecules. The reaction relies on enzymatic activity and the transfer of energy from glyceraldehyde-3-phosphate.
Step-by-step explanation:
Glycolysis begins with the phosphorylation of glucose by hexokinase to form glucose-6-phosphate. This step uses one ATP, which is the donor of the phosphate group. Under the action of phosphofructokinase, glucose-6-phosphate is converted into fructose-6-phosphate.
At this point, a second ATP donates its phosphate group, forming fructose-1,6-bisphosphate. This six-carbon sugar is split to form two phosphorylated three-carbon molecules, glyceraldehyde-3-phosphate and dihydroxyacetone phosphate, which are both converted into glyceraldehyde-3-phosphate.
The glyceraldehyde-3-phosphate is further phosphorylated with groups donated by dihydrogen phosphate present in the cell to form the three-carbon molecule 1,3-bisphosphoglycerate. The energy of this reaction comes from the oxidation of (removal of electrons from) glyceraldehyde-3-phosphate.