Question

the two substrates involved in substrate - level phosphorylation during the payoff phase are: glyceraldehyde 3 - phosphate (g3p) and 3 - phosphoglycerate(3pg) glyceraldehyde 3 - phosphate (g3p) and phosphoenolpyruvate (pep) 1,3 - biphosphoglycerate and 2 - phosphoglycerate(3pg) 1,3 - biphosphoglycerate and phosphoenolpyruvate (pep) pyruvate and phosphoenolpyruvate (pep) 17 multiple choice 1 point during lactic acid fermentation, pyruvate: regenerates nadh from the reduction of pyruvate. generates atp from the reduction of pyruvate. regenerates nad+ from the oxidation of pyruvate. regenerates nad+ from the reduction of pyruvate. generates atp from the oxidation of pyruvate. 18 multiple choice 1 point in the cleavage phase of glycolysis: phosphate groups are added to glucose atp is generated by substrate - level phosphorylation nad+ is reduced to nadh an unstable fructose 1,6 - biphosphate is cleaved into 2 molecules of pyruvate an unstable fructose 1,6 - biphosphate is cleaved into 2 molecules of glyceraldehyde 3 - phosphate (g3p)

Explanation:

1. In the pay - off phase of glycolysis, the two substrates involved in substrate - level phosphorylation are 1,3 - Bisphosphoglycerate and Phosphoenolpyruvate (PEP). 1,3 - Bisphosphoglycerate donates a phosphate group to ADP to form ATP, and Phosphoenolpyruvate also transfers a phosphate group to ADP to generate ATP through substrate - level phosphorylation.
2. During lactic acid fermentation, pyruvate is reduced by NADH to form lactate, which regenerates NAD+ to keep glycolysis going. This is important for cells to continue generating ATP under anaerobic conditions.
3. In the cleavage phase of glycolysis, an unstable fructose 1,6 - bisphosphate is cleaved into 2 molecules of glyceraldehyde 3 - phosphate (G3P). This step splits the 6 - carbon sugar into two 3 - carbon molecules.

Answer:

1. D. 1,3 - Bisphosphoglycerate and Phosphoenolpyruvate (PEP)
2. D. regenerates NAD+ from the reduction of pyruvate
3. E. An unstable fructose 1,6 - bisphosphate is cleaved into 2 molecules of glyceraldehyde 3 - phosphate (G3P)