Question

Which order of molecular conversions is correct for the Calvin cycle?

$$\begin{gathered} a.RuBP+G3P\to 3-PGA\to sugar \\ b.RuBisCO\to C{o}_2\to RuBP\to G3P \\ c.RuBO+C{o}_2\to \left\{RuBisCO\left.\right\}\right.3-PGA\to G3P \\ d.C{o}_2\to 3-PGA\to RuBP\to G3P \end{gathered}$$

Short answer

The $RuBisCO$enzyme is regenerated throughout the Calvin cycle and has a strong affinity for $C{o}_2$As a result, option c.

Step-by-step solution

Introduction

Calvin cycle is a cycle of light-independent reactions that involves the formation of glucose from carbon dioxide.

 Incorrect answer (a), (b) and (d)

$C{o}_2$(carbon dioxide) is needed along with $RuBP$(ribulose, bisphosphate) to produce $G3P$(glyceraldehyde, phosphate).

Ribulose, bisphosphate carboxylase /oxygenase$RuBP$ is an enzyme that is used to initiate the reaction between and in the cycle.

$RuBP$and$G3P$ are involved in initiation of the Calvin cycle.

Hence, the options a, b, and d. are incorrect.

correct answer (c) explanation

Rubisco catalyzes the reaction of carbon dioxide and RuBP to form $3-$PGA ($3-$Phosphoglycerate ). NADPH ( reduced nicotinamide adenine dinucleotide phosphate) and ATP (adenosine triphosphate) produced during the light-dependent reactions are also used to convert $3-$PGA molecules into G$3$P