Limiting Factors (calvin cycle) Flashcards
0
Q
What happens to the Calvin cycle in bright light?
A
- more excitation of electrons so more photophosphorylation
- lots of ATP + NADPH from light dependent reaction so lots of TP as a as GP is converted to TP quickly
- low levels of GP as it is quickly converted to TP
- because there is lots of TP there will be lots converted to RuBP, increasing the conc of RuBP
1
Q
What happens to the Calvin cycle in dim light?
A
- very small amounts of ATP + NADPH from light dependent reaction
- not much conversion of GP to TP so the conc of GP increases and the conc of TP decreases
- because there is a low conc of TP there is a low conc of RuBP
2
Q
What happens to the Calvin cycle in high CO2 concentration?
A
- high conc of GP as RuBP is quickly converted to GP so the conc of TP is also high
- conc of RuBP is low as all available RuBP IS quickly converted to GP
However open stomata may lead to increased transpiration
- so the plant may wilt if the water loos exceed water uptake - this leads to a stress repos she and following the release of abscisic acid the stomata close reducing the Co2 uptake and therefore the rate of photosynthesis
3
Q
What happens to the Calvin cycle in low CO2 concentration?
A
- because CO2 is limiting, conc of GP is low
- because there is a low conc of GP, conc of TP is also low as not much GP is converted to TP
- there is a high conc of RuBP as not much is converted to TP so it builds up