photosynthesis light independent

Question 1

what are the 3 main stages of the calvin cycle (light independent reaction)

Answer 1

carbon fixation
reduction
RuBP regeneration

Question 2

what occurs during carbon fixation

Answer 2

carbon dioxide diffuses into the chloroplast and reacts with RuBP(ribulosebisphosphate)
this is catalysed by RuBisCO (ribulosebisphosphate carboxylase)
forms a 6 carbon compound which is very unstable so it splits into 2, more stable 3 carbon compounds called glycerate-3-phosphate

Question 3

what occurs during reduction

Answer 3

each glycerate-3-phosphate is phosphorylated by ATP
the ATP also reduces the GP using hydrogens from NADPH becoming triose phosphate
1 triose phosphate molecule leaves the calvin cycle to make glucose

Question 4

what occurs during the regeneration of rubp

Answer 4

the triose phosphate is phosphorylated by ATP and becomes RuBP

Question 5

if only one triosphosphate molecule returns to reform RuBP after one calvin cycle

Answer 5

in the balanced equation of photosynthesis there are 6 carbons so 6 calvin cycles occur at one time per reaction
in total this means 2 triosphosphates leave and 10 return (30 carbons) enough to reform 6 RuBP