Question

For the phase two of glycolysis, indicate in which order the following enzymes catalyze the correct sequence of reactions:

a) Hexokinase, Phosphofructokinase, Pyruvate Kinase
b) Aldolase, Triose Phosphate Isomerase, Phosphoglycerate μtase
c) Enolase, Pyruvate Kinase, Phosphofructokinase
d) Glucose-6-phosphate isomerase, Phosphofructokinase, Hexokinase

Answer 1

The correct order of enzymes catalyzing reactions in the second phase of glycolysis is represented by Aldolase, Triose Phosphate Isomerase, and Phosphoglycerate mutase (option b).

Step-by-step explanation:

In the second phase of glycolysis, the correct sequence of enzymes that catalyze the reactions are represented by option b) Aldolase, Triose Phosphate Isomerase, Phosphoglycerate mutase. After the first half of glycolysis where glucose is converted into two molecules of glyceraldehyde-3-phosphate, these enzymes perform the following functions: Aldolase cleaves the six-carbon fructose-1,6-bisphosphate into two three-carbon molecules, glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. Then, Triose Phosphate Isomerase converts dihydroxyacetone phosphate into a second molecule of glyceraldehyde-3-phosphate, thus ensuring both molecules entering the second phase are the same. Finally, Phosphoglycerate mutase facilitates the transformation of 3-phosphoglycerate into 2-phosphoglycerate, proceeding down the glycolytic pathway.