Final answer:
Fructose-1,6-bisphosphate is split into two three-carbon molecules, glyceraldehyde-3-phosphate and dihydroxyacetone phosphate, by the enzyme aldolase during the cleavage stage of glycolysis.
Step-by-step explanation:
During the cleavage stage of glycolysis, fructose-1, 6-bisphosphate is broken down into two three-carbon molecules: glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. This reaction is facilitated by the enzyme aldolase. The enzyme triosephosphate isomerase then converts the dihydroxyacetone phosphate into an additional molecule of glyceraldehyde-3-phosphate. As a result, fructose-1,6-bisphosphate yields a total of two glyceraldehyde-3-phosphate molecules, which marks the transition from the energy-investment phase to the energy-generation phase of glycolysis.