Dark Reactions, Calvin Cycle.
Hi! Guys, What is up. Today we are going to look at the dark reactions which is a series of 13 reactions from photosynthesis. Melvin Calvin was the scientist who studied these reactions and was awarded nobel prize in 1972.
As the name suggests these reactions don`t require light and chlorophyll to take place. They take place in the stroma of the chloroplasts. To understand these reactions, dark reactions have been divided into 3 phases.
1) Carbon Fixation.
In this phase Carbondioxide reacts with Ribulose biphostphate to for 2 Phosphoglycerate molecules.
2) Reduction.
During this phase 2 PGA molecules react with 2 ATP molecules formed in the light reactions resulting in the formation of 2 DPGA molecules.
2 DPGA molecules reacts with 2 NADPH formed in light reactions resulting in the formation of 6 PGAL molecules.
3) Uses of PGAL.
PGAL molecules form C3, C4, C5, C6 and C7 compounds and one of them converts to glucose phosphate which later reacts with oxygen to form glucose.