Glycolysis is the metabolic pathway that converts glucose C6H12O6 into pyruvate CH3COCOO + H+ . During this process, a net yield of 2 ATP molecules is produced per glucose molecule. Glycolysis occurs in the cytoplasm of cells and consists of 10 enzyme-catalyzed reactions, which can be divided into two main phases: the energy investment phase and the energy generation phase.1. Energy Investment Phase:Step 1: Phosphorylation of glucoseGlucose is phosphorylated by hexokinase to form glucose-6-phosphate G6P . This step consumes 1 ATP molecule.Reaction: Glucose + ATP Glucose-6-phosphate + ADPStep 2: Isomerization of glucose-6-phosphateGlucose-6-phosphate is converted to its isomer, fructose-6-phosphate F6P , by the enzyme phosphoglucose isomerase.Reaction: Glucose-6-phosphate Fructose-6-phosphateStep 3: Phosphorylation of fructose-6-phosphateFructose-6-phosphate is phosphorylated by phosphofructokinase to form fructose-1,6-bisphosphate F1,6BP . This step consumes another ATP molecule.Reaction: Fructose-6-phosphate + ATP Fructose-1,6-bisphosphate + ADPStep 4: Cleavage of fructose-1,6-bisphosphateFructose-1,6-bisphosphate is cleaved by aldolase into two 3-carbon molecules: glyceraldehyde-3-phosphate G3P and dihydroxyacetone phosphate DHAP .Reaction: Fructose-1,6-bisphosphate Glyceraldehyde-3-phosphate + Dihydroxyacetone phosphateStep 5: Interconversion of dihydroxyacetone phosphate and glyceraldehyde-3-phosphateDihydroxyacetone phosphate is converted to glyceraldehyde-3-phosphate by the enzyme triose phosphate isomerase.Reaction: Dihydroxyacetone phosphate Glyceraldehyde-3-phosphate2. Energy Generation Phase:Step 6: Oxidation and phosphorylation of glyceraldehyde-3-phosphateGlyceraldehyde-3-phosphate is oxidized and phosphorylated by glyceraldehyde-3-phosphate dehydrogenase to form 1,3-bisphosphoglycerate 1,3BPG . This step generates 2 NADH molecules one per G3P .Reaction: 2 Glyceraldehyde-3-phosphate + 2 NAD+ + 2 Pi 2 1,3-Bisphosphoglycerate + 2 NADH + 2 H+Step 7: Phosphoryl transfer1,3-bisphosphoglycerate transfers a phosphate group to ADP, forming 3-phosphoglycerate 3PG and ATP. This step generates 2 ATP molecules one per 1,3BPG .Reaction: 2 1,3-Bisphosphoglycerate + 2 ADP 2 3-Phosphoglycerate + 2 ATPStep 8: Isomerization of 3-phosphoglycerate3-phosphoglycerate is converted to 2-phosphoglycerate 2PG by the enzyme phosphoglycerate mutase.Reaction: 2 3-Phosphoglycerate 2 2-PhosphoglycerateStep 9: Dehydration of 2-phosphoglycerate2-phosphoglycerate is dehydrated by enolase to form phosphoenolpyruvate PEP .Reaction: 2 2-Phosphoglycerate 2 Phosphoenolpyruvate + 2 H2OStep 10: Phosphoryl transferPhosphoenolpyruvate transfers a phosphate group to ADP, forming pyruvate and ATP. This step generates 2 ATP molecules one per PEP .Reaction: 2 Phosphoenolpyruvate + 2 ADP 2 Pyruvate + 2 ATPIn summary, glycolysis produces a net yield of 2 ATP molecules, 2 NADH molecules, and 2 pyruvate molecules per glucose molecule. The energy investment phase consumes 2 ATP molecules, while the energy generation phase produces 4 ATP molecules, resulting in a net gain of 2 ATP molecules.