calvin cycle Flashcards
where does the calvin cycle occur
in the stroma
what are the products of the calvin cycle
triose phosphate, ribulose bisphosphate
what does the calvin cycle require to keep going
ATP and H+ ions
what is the starting product of the calvin cycle
ribulose bisphosphate, which is constantly regenerated
where does CO2 enter the plant
through the leaf via the stomata
how does CO2 reach the stroma
diffuses from the stomata
when CO2 reaches the stroma, what happens to it
combined with RuBP (5-C compound) to form an unstable 6 carbon compound, which rapidly breaks into two 3 carbon compounds called GP
what enzyme catalyses the reaction between RuBP and CO2
RuBisCO
how is GP converted into triose phosphate
using ATP (x2) from the light dependant stage
other than ATP, what else is required to convert GP into triose phosphate
requires H+ ions from reduced NADP in the light dependant reaction (x2)
what is triose phosphate then used for
making useful organic compounds
how does triose phosphate make glucose and other hexose sugars
joining together 2 triose phosphate molecules
what other compounds can triose phosphate also be used to make
lipids and it synthesises glycerol
what is GP used to make
makes fatty acids of lipids and some amino acids
how many molecules of TP is produced from 3 turns of the calvin cycle
6 molecules of TP
what are 5 of the 6 molecules of TP produced from 3 turns of the calvin cycle used for
regenerating RuBP
as 5 out of the 6 molecules get used to regenerate RuBP, how many times must the calvin cycle turn to produce a hexose sugar
3 turns would produce 1 molecule of TP (3 carbon) so 6 turns would produce 2 molecules of TP (2x3 carbon)
glucose is a hexose sugar, so therefore needs to turn 6 times
how much ATP and reduced NADP from the light dependant reaction is needed to turn the calvin cycle 6 times
18 ATP and 12 NADP reduced
how is RuBP regenerated
using triose phosphate and the rest of the ATP produced by the light dependant reaction
