Question

The enzyme pair common to $C_3$ plants and EMP is

• A. Cytochrome oxidase and enolase
• B. Aldolase and triose phosphate isomerase
• C. Aldolase and enolase
• D. Phosphoglyceromutase and triose phosphate isomerase

Answer 1

The correct option is B Aldolase and triose phosphate isomerase

Triose phosphate isomerase enzyme is common to both $C_3$ plants and EMP pathway that catalyze the interconversion of glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. In $C_3$ cycle, aldolase enzyme catalyzes the reversible condensation of glyceraldehyde 3-phosphate and dihydroxyacetone phosphate into fructose 1,6-bisphosphate as well as condensation of erythrose 4-phosphate and dihydroxyacetone phosphate to obtain sedoheptulose 1,7-bisphosphate. Reversible aldol condensation of fructose 1,6-bisphophate into glyceraldehyde 3-phosphate and dihydroxyacetone phosphate during EMP is catalyzed by aldolase. Thus, the correct answer is option B.