The Calvin Cycle Flashcards
Calvin and his co-workers then worked out the whole pathway and showed
that the pathway operated in a cyclic manner; the RuBP was regenerated.
the Calvin
pathway occurs in all photosynthetic plants; it does not matter whether
they have C3
or C4
(or any other) pathways (Figure 11.8).
For ease of understanding, the Calvin cycle can be described under
three stages: carboxylation, reduction and regeneration.
1
the Calvin cycle can be described under
three stages: carboxylation, reduction and regeneration.
- Carboxylation–
1.Carboxylation is the fixation of CO2 into a stable organic
intermediate.
2. Carboxylation is the most crucial step of the Calvin cycle
where CO2 is utilised for the carboxylation of RuBP.
3.This reaction is catalysed by the enzyme RuBP carboxylase which results in the formation
of two molecules of 3-PGA. 4.Since this enzyme also has an oxygenation activity it would be more correct to call it RuBP carboxylase-oxygenase
or RuBisCO.
Reduction –
1.These are a series of reactions that lead to the formation of …
2.The steps involve ….and ….
3.The fixation of …molecules of CO2 and … of the cycle are required for the formation of one molecule of glucose from the pathway.
1.glucose
2.utilisation of 2 molecules of ATP for phosphorylation ,
two of NADPH for reduction per CO2 molecule fixed.
3.six ,
6 turns
- Regeneration –
- Regeneration of the CO2 acceptor molecule … is crucial if the cycle is to continue uninterrupted.
2.The regeneration steps require … for phosphorylation to form RuBP
3.Hence for every CO2 molecule entering the Calvin cycle, … molecules of ATP and … of NADPH are required. It is probably to meet this differencein number of ..nd..used in the dark reaction that the cyclic phosphorylation takes place.
1.RuBP
2.one ATP
3.3,2,
ATP and NADPH
To make one molecule of glucose …. of the cycle are required.
6 turns
In Out
Six CO2 ….
18 ATP ….
12 NADPH ….
Out
One glucose
18 ADP
12 NADP
Plants that are adapted to dry tropical regions have …pathway mentioned earlier.
.
