Light independent stage

How does the Calvin cycle start?

ATP and NADPH generated in the light dependent stage is use to produce glucose from CO2 in the stroma

What is CO2 catalysed by?

Rubisco, which catalyses the reaction between CO2 and ribulose biphosphate (RuBP) forming an unstable 6 carbon molecule

What immediately happens to the unstable 6 carbon molecule?

This immediately splits to form 2 three-carbon molecules called GLYCERATE 3-PHOSPHATE (GP)  (carbon fixation)

What do the NADPH and ATP do?

Provide energy and phosphate groups to change GP into a 3 carbon sugar, TP. This is the first carbohydrate to be produced. NADPH reduces GP to TP, NADPH is oxidised into NADP

What do some TP molecules do?

Goes to make glucose. The remainder is converted into a hexose phosphate from which glucose, fructose, sucrose, starch and cellulose can be formed

What else is GP used to synthesise?

Fatty acids and amino acids

How many turns of the cycle are needed to make 6 molecules of TP?

As most of the TP is recycled to form RuBP,  (which requires ATP) the cycle needs 3 turns to produce six molecules of TP as 2 molecules of TP are made from every molecule of CO2

What are 5 out of 6 used to regenerate?

RuBP. Only 1 TP molecule is used to make the hexose sugar

How many times does the cycle turn to produce 1 molecule of a hexose sugar?

As a hexose sugar has 6 carbons, the cycle must turn 6 times to produce 1 molecule of a hexose sugar

What do 6 turns of the cycle produce?

18 ATP and 12 NADPH molecules from the light dependent stage

Why does temperature have a greater effect on the rate of LIS?

Controlled by enzymes, higher temp increases KE and number of successful collisions, enzymes may denature at high temps