Question

First, ______ phosphorylates 3-PGA at the carboxyl group, yielding a mixed anhydride. Then, ________ reduces the mixed anhydride to 6 molecules of G3P.

a. RuBisCO; NADPH
b. ATP; NADH
c. PEP Carboxylase; FADH₂
d. Hexokinase; ATP

Answer 1

The enzymes involved in phosphorylation and reduction of 3-PGA in the Calvin cycle are RuBisCO and NADPH, which catalyze the production of 3-PGA and its subsequent reduction to G3P, respectively.

Step-by-step explanation:

The student's question is about the enzymes involved in the Calvin cycle, specifically the stages of phosphorylation and reduction of 3-phosphoglycerate (3-PGA). The correct answers to the blanks are RuBisCO and NADPH, respectively.

During the Calvin cycle, RuBisCO initially catalyzes the reaction of CO₂ with ribulose bisphosphate (RuBP), resulting in the production of 3-PGA. Subsequently, the 3-PGA molecules undergo a reduction reaction where they are phosphorylated by ATP, generating a mixed anhydride intermediate, which is then reduced by NADPH to form glyceraldehyde 3-phosphate (G3P).