light independent reaction

Question 1

explain the process of the light independent reaction

Answer 1

1. CO2 enters the stroma by diffusion
   Rubisco catalyses the reaction between 5 carbon ribulose bisphosphate (RuBP) and 1 carbon CO2 molecule
2. this forms an unstable 6 carbon chain that breaks instantly due to it’s instability to form 2 molecules of glycerate 3 phosphate (G3P)
3. ATP hydrolysis and NaDPH provide the energy for the reduction of glycerate 3 phosphate (G3P) to 2 molecules of triose phosphate (3C)
4. some of this triose phosphate is then used to make organic molecules (e.g: glucose)
5. hydrolysis of ATP provides the energy for the conversion of triose phosphate (TP) back to ribulose bisphosphate (RuBP)

Question 2

describe the roles of ATP and reduced NaDP in the light independent reaction

Answer 2

ATP: phosphate is required to convert glycerate - 3 - phosphate (G3P) into triose phosphate (TP) and TP back into RuBP

reduced NaDP: required to reduce glycerate 3 phosphate (G3P) into triose phosphate (TP)

Question 3

where does the light independent reaction occur

Answer 3

stroma
(of chloroplasts)