Question

Why is the third stage of the Calvin cycle called the regeneration stage?

a) Regenerates NADP+
b) Regenerates RuBP
c) Regenerates G3P
d) Regenerates ATP

Answer 1

The third stage of the Calvin cycle is called the regeneration stage because it regenerates RuBP, which is essential for carbon fixation. Five out of six molecules of G3P are reused to recreate RuBP.

Step-by-step explanation:

The third stage of the Calvin cycle is called the regeneration stage because it regenerates RuBP (ribulose-1,5-bisphosphate), which is an essential molecule for the process of carbon fixation. In this stage, five out of the six molecules of G3P (glyceraldehyde-3-phosphate) produced in the previous stages are reused to recreate the initial five molecules of RuBP. By regenerating RuBP, the cycle is able to continue and prepare for more CO₂ to be fixed.