Final answer:
During the second half of glycolysis, ATP, NADH, and pyruvate are produced. These include the synthesis of ATP via substrate-level phosphorylation, the generation of NADH from the oxidation of glyceraldehyde-3-phosphate, and the conversion of intermediates into pyruvate.
Step-by-step explanation:
Molecules Produced During the Last Steps of Glycolysis
The student asked which molecules are produced during the second half of glycolysis. During the last five steps of glycolysis, several key molecules are generated. These include ATP (adenosine triphosphate), NADH (nicotinamide adenine dinucleotide + hydrogen), and pyruvate. ATP is synthesized from ADP in steps that involve substrate-level phosphorylation. NADH is produced when the sugar glyceraldehyde-3-phosphate is oxidized and phosphorylated, creating 1,3-bisphosphoglycerate. Pyruvate is the final product of glycolysis, which is formed through further metabolic reactions. Option 4, glucose, is incorrect because it is not produced in the second half of glycolysis; it is the initial substrate that enters the pathway.
The energy-releasing steps of glycolysis ultimately lead to the formation of two molecules of ATP and NADH per initial molecule of glucose, after adjusting for the two ATPs used in the early stages. Hence, there is a net profit of two ATPs and the creation of two NADHs. Each 3-carbon sugar molecule derived from the original glucose molecule goes through these steps, doubling the output. Moreover, these steps don’t require new ATP investment, as the necessary phosphate groups are liberated from organic intermediates.