Question

It can be useful to analyze the steps of glycolysis with respect to the four basic types of enzymes required by this central catabolic pathway and to consider whether each enzyme produces or harvests the energy of an activated carrier.

For each step of glycolysis (see Figure 13–5 or Panel 13–1), A) indicate which type of enzyme (of the four listed below and in Table 13–1 is required—or ‘other’). B) Indicate whether an activated energy carrier is involved, and, if so, how. C) Describe the chemical changes that occur between the substrates and products of each step. Enzyme types: kinase, isomerase, mutase, dehydrogenase

Step 1 enzyme ___________

Step 2 enzyme ___________

Step 3 enzyme ___________

Step 4 enzyme ___________

Step 5 enzyme ___________

Step 6 enzyme ___________

Step 7 enzyme ___________

Step 8 enzyme ___________

Step 9 enzyme ___________

Step 10 enzyme ___________

Do you expect the cell to produce more ATP from one glucose molecule or from one fatty acid molecule? Justify your answer by describing the chemical structure, the relative oxidation level of the carbons, and how each feeds into cell respiration.

In step 7 of the citric acid cycle, fumarase catalyzes the addition of a water molecule to a carbon–carbon double bond (see Panel 13­–2). Can this be considered an oxidation reaction? Explain your answer.

Answer 1