Unit 5, photosynthesis light independent (Calvin cycle) Flashcards
Where does the LIR reaction take place?
- stroma
What enzyme does the fluid in the stroma contain?
Rubisco
What are the key molecules in the LIR stage?
- co2, reduced NADP and ATP to make up a hexose sugar
What is the ATP used for?
-It is hydrolysed to provide energy for the reaction
What is the reduced NADP used for ?
It donates the hydrogen to GP to make the NADP deoxidised and to make it a reduction reaction
What occurs in the 4 stage Calvin cycle?
1) co2 from atmosphere that has gone through stomata reacts with RuBP to form two GP. This is catalysed by the enzyme rubisco .
2) GP is reduced to TP using energy from a hydrolysed ATP and accepting a hydrogen from reduced NADP ( reoxiding NADP), causing this reaction to be a reduction reaction
3) the cycle is repeated 6 times, each time a carbon is removed from TP, to form a hexose sugar, which can be converted into an organic substance
4) the rest of the top molecule is used to regenerate RuBP, with the energy from ATP.
What are the limiting factors to photosynthesis?
Temperature- in the LIR due to the usage of an enzyme
Co2 concentration- in the LIR, main reactant in Calvin cycle
Light intensity - LDR
water stress- photosynthesis amounts reduce , to compensate for loss of water the plant produces abiscic acid which causes the stomata
What is the importance of knowing the limiting factors to farmers?
- farmers require optimum photosynthesis, to do this they can manipulate practices
How do farmers manipulate practices to causes photosynthesis to be the optimum?
- artificial lighting for light intensity
- heating a greenhouse to increase temperature
- burning fuel to release more co2 by a parrafin burner
What do farmers have to consider when manipulating practices to improve photosynthesis?
- profit, is the amount of photosynthesis and growth cost effective?
