What is the first part of the Calvin cycle?

1 Answer
Saliha · Kate M.
Nov 5, 2017

CarbonCarbon fixation

Explanation:

It refers to the initial incorporation of CO_2CO2 into organic material. We will follow 33 molecules of CO_2CO2 through the reaction because we want sugars(carbohydrates) as the end product of cycle. And for this, at least 33 molecules of CO_2CO2 are necessary.

Because;
33 molecules of CO_2CO2to → contain 33 C toC→ so at least they will give 11 carbohydrate molecule( a triose).

  • Calvin cycle begins by the reaction of CO_2CO2 with highly reactive phosphorylated five carbon-sugar named ribulose bisphosphate(RuBP).
  • This reaction is catalyzed by the enzyme ribulose bisphosphate carboxylase also known as Rubisco.
  • The product of this reaction is highly unstable six-carbon intermediate that immediately breaks into two molecules of three-carbon-compound named 33-phosphoglycerate(PGA).
  • The carbon that was originally a part of CO_2CO2 molecule is now a part of an organic compound which means carbon has been fixed.
    enter image source here

https://www.khanacademy.org/science/biology/photosynthesis-in-plants/the-calvin-cycle-reactions/a/calvin-cycle

Note:Note:
Rubisco is the most abundant protein in the chloroplast and probably the most abundant protein on Earth.

Related questions
See all questions in Plant Nutrition & Transport
Impact of this question
6630 views around the world
You can reuse this answer
Creative Commons License