Light InDependent Reactons/clavin Cycle

Question 1

What is Calvin cycle process

Answer 1

Process of Calvin cycle is
1) C02 combines with RuBP (needed for Carbon fixation) (reaction is catalysed RuBISCO)
2) 6carbon compound formed is unstable and breaks down into 2 3Carbon molecules (GP)
3)reduced NADP reduces (gives Hydrogen) to GP (glucose 6phosphate) it turns into GALP.
4)breakdown of ATP provides energy for this endothermic reaction
5)2 of 12 GALP molecules allow creation of hexose-can be converted into organic compounds e.g glucose
6) 10/12 GALPs are phosphorylated to generate 6RuBP
ATP provides phosphate.
Takes place in stroma during LIR

Question 2

Where do LIR take place

Answer 2

LIR take place in stroma

Question 3

What is function of NADP in LIR

Answer 3

Function of NADP in LIR is to act as a hydrogen carrier (which prevents hydrogen reacting with 02 released in photolysis)

Question 4

What is carbon fixation

Answer 4

Carbon fixation is when carbon is fixed in organic molecules (initially GP)making it available to other organisms.

Question 5

What is role of ATP in LIR

Answer 5

Role of ATP in LIR are to provide energy for endothermic reactions (GP to GALP) and provide phosphate for RuBP (regenerating)

Question 6

What is role of reduced NADP in LIR

Answer 6

Role of reduced NADP in LIR is to provide hydrogen for reduction of GP to GALP

Question 7

How is ATP made available for LIR

Answer 7

ATP is made available for LIR bu:
Sunlight excites electrons to higher energy levels and so they leave chlorophyll. Passed from electron carrier to electron carries in a series of redox reactions. PhotoPhosphorylation generates ATP

Question 8

Why is carbon fixation important and what are benefits of having faster carbon fixation

Answer 8

Carbon fixation is important because it produces GP and this can be converted into organic molecules e.g sugar
Benefits of having faster carbon fixation are: GP it converted into organic molecules e.g starch quicker and increases rate of growth of plant.

Question 9

Why would LDR stop if there was an absence of CO2

Answer 9

LDR would stop in absence of CO2 because reduced NADP would not give up H, ATP would not be hydrolysed so reactants for LDR Arun IHT.

Question 10

Why may light hitting surface of leaf not be used by chloroplast

Answer 10

Light hitting surface of leaf may not be used by chloroplasts because:
Light reflects of leaf
Incorrect wavelength
Doesn’t hit chloroplasts

Question 11

What is role of RUBISCO

Answer 11

Role of RUBISCO IS:

enzyme in Calvin cycle involved in carbon fixation (bonding of C02 to RuBP) to form GP