Light Independent Stage of photosynthesis

HideShow resource information
  • Created by: Steff06
  • Created on: 06-02-16 11:11
State the 4 stages of the Calvin cycle
1. The carbon fixation stage, 2. The reduction stage, 3. Food synthesis stage, 4. Regeneration stage.
1 of 11
Stomatal guard cells only contain PSI/can't perform non cyclic photophosphorylation. What use is cyclic-photophsorylation to them?
Osmosis controls amount of H2O in guard cells. ATP can actively transport K+ ions into guard cells which become turgid due to entry of water. Enables CO2 to diffuse into plant, increases rate of photosynthesis.
2 of 11
What did Calvin and his co-workers determine?
The chemical steps involved in the reduction of carbon dioxide to carbohydrate.
3 of 11
Where does the Calvin cycle take place?
In the stroma of chloropasts.
4 of 11
Describe phase 1 of the Calvin cycle
CO2+ribulose bisphosphate(RuBP)- fixation. CO2 enters leaf through stomata +diffuses into stroma. CO2 combines with RuBP to form unstable 6-carbon compound. Compound broken down into two molecules of glycerate-3-phosphate. Rubisco catalyses reaction.
5 of 11
Describe phase 2 of the Calvin Cycle
ATP+reduced NADP reduce GP to TP. ATP provides energy and H+ ions from NADPH2 required. Reduced NADP recycled to NADP. Triose phosphate converted to glucose and other useful compounds.
6 of 11
Describe phase 3 of the Calvin Cycle
RuBP is regenerated. 5 out of 6 molecules of TP are used to regenerate RuBP. 6th molecule is used to produce glucose. 6 turns of cycle needed to produce 1 glucose.
7 of 11
What are TP and GP used to make?
Carbohydrates, lipids and proteins.
8 of 11
How many turns does the Calvin cycle need to make 1 hexose sugar and explain.
6. 2 TP are produced per cycle. 3 turns = 6 TP. 5 out of 6 used to regenerate RuBP. 1 ATP/3 carbon left. 3 more turns = 2 TP and 6 carbons altogether. 2TP, 18ATP, 12 reduced NADP needed to make 1 hexose sugar.
9 of 11
Describe the changes in the amount of GP and RuBP in light.
In light, both GP and RuBP remain at a steady level. RuBP is converted into GP which is converted into RuBP in regeneration stage.
10 of 11
Describe the changes in the amounts of GP and RuBP in darkness.
In dark, GP accumulates and levels of RuBP fall. This provides evidence that the Calvin cycle is disrupted in darkness. Reduction of GP - TP requires ATP + NADPH2 from light dependent stage. Formation of TP prevented and no regeneration of RuBP.
11 of 11

Other cards in this set

Card 2

Front

Stomatal guard cells only contain PSI/can't perform non cyclic photophosphorylation. What use is cyclic-photophsorylation to them?

Back

Osmosis controls amount of H2O in guard cells. ATP can actively transport K+ ions into guard cells which become turgid due to entry of water. Enables CO2 to diffuse into plant, increases rate of photosynthesis.

Card 3

Front

What did Calvin and his co-workers determine?

Back

Preview of the front of card 3

Card 4

Front

Where does the Calvin cycle take place?

Back

Preview of the front of card 4

Card 5

Front

Describe phase 1 of the Calvin cycle

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Cellular processes resources »