light independent reaction (Calvin Cycle)

where does the light independent reactions occur ?

occurs int he troma of the chloroplast

why do light dependent reactions occur in the stroma and not the thylakoid ?

because specific enzymes that catalys the reaction are present in the stroma and not the thylakoid

what do light dependent reactions provide light independent reactions with ?

provide it with NADPH and ATP

what is the CO2 acceptor in the calvin cycle ?

ribulose biphosphate (RuBP)

what catalyses the reaction between RuBP and carbon in the calvin cycle ?

rubisco catalyses this reaction

How is glycerate 3 phosphate oxidised to form triose phosphate ?

because it is gaining a H+

what is the product of the light independent reaction ?

glusose is the product

what are other organic molecules formed as a result in the calvin cycle ?

• sucrose

• amino acids

• starch

• cellulose

• lipids

• nucleic acids

can you do light independent reactions at night any why/ why not ?

no as light is needed to make ATP and NADPH

how many times does the calvin cycle need to take place to made a molecule of glucose ?

6x as one cycle releases 1x C atom and we need 6 for a molecule of glucose

what are the steps of the calvin cycle ?

1. Fixation of CO2

• CO2 combineds with RuBP (ribulose bisphosphate, a 5 carbon sugar) in reaction catalysed by enzyme rubisco

• resulting in instable 6 carbon compound & splits into 2 molecules of glycerate 3-phosphate (GP), 3 carbon molecules

2. reduction of glycerate 3-phosphate to triose phosphate-

• ATP and reduced NADP are used to reduce GP to triose phosphate

3. regeneration of ribulose biphosphate

• ATP used to convert 5 of the 6 carbons present into the 2 triose phosphate molecules back into RuBP

4. the production of useful organic substances

• remaining triose phosphate molecules used to produce useful organic molecules needed by plant e.g. starch, cellulose ,lipids, proteins

how are the chloroplasts adapted for light independent reactions ?

• fluid in stroma contain all enzymes needed

• products from light dependent reaction can easily diffuse into the stroma

• contains DNA & ribsomoses to easily manufacture proteins for light independent reaction