Final answer:
During glycolysis, two ATP molecules are consumed in the energy-consuming phase to convert glucose into glucose-6-phosphate. In the subsequent steps, fructose-6-phosphate is formed, and two glyceraldehyde-3-phosphate molecules are generated. Each glyceraldehyde-3-phosphate molecule produces one ATP molecule, resulting in a total of four ATP molecules generated during glycolysis.
Step-by-step explanation:
Glycolysis is the metabolic pathway that converts glucose into pyruvate, generating ATP and NADH in the process. During the energy-consuming phase of glycolysis, two ATP molecules are consumed and transferred to the glucose molecule, forming glucose-6-phosphate. The glucose-6-phosphate is further converted to fructose-6-phosphate through the action of phosphofructokinase. This reaction requires another ATP molecule. The fructose-6-phosphate is then split into two three-carbon compounds, glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. Each glyceraldehyde-3-phosphate is converted into 1,3-bisphosphoglycerate, generating NADH in the process. Finally, each 1,3-bisphosphoglycerate is dephosphorylated by phosphoglycerate kinase, resulting in the formation of two ATP molecules. So, a total of four ATP molecules are produced during glycolysis.