[Biology][Practical-16] Photososynthesis Questions

[AriHoresh]

PHOTOSYNTHESIS

• Phtosynthesis occurs in the chloroplast

• What is the general reaction of photosynthesis?

• What are the differences between cyclic and non cyclic photophosporylation?

• What are the 2 phases of photosynthesis?

1. light dependant reactions
2. light-independent reactions
   
   

• What are the 3 steps of photosynthesis?

1. light excites chlorophyll electrons and they become energized
2. excited electrons pass through electron transport chain, making ATP via chemiosmosis
3. electrons may reduce NADP+ and be replaced by photolysis of water

• What happens in light dependant reactions?

• Photosystems are photosynthetic pigments embedded within the thylakoid membrane

• In cyclic photophosphorylation, only PSI is involved, water is not required oxygen is not evolved, and NADPH is not synthesized

• Cyclic photophosphorylation is used to produce additional ATP in order to meet cell energy demands

• In non-cyclic photophosphorylation, PSI and PSII are involved, photolysis of water is required, oxygen is devolved, and NADH is synthesized

• Photosystem I absorbs light at 700nm and photosystem II absorbs light at 680nm

• What are the steps of the Calvin cycle?

• Carboxylation of ribulose bisphosphate
• Reduction of glycerate-3-phosphate
• Regeneration of ribulose bisphosphate

• The proton gradient will be used by ATP synthase to create ATP from ADP+Pi

• What happens in light-independent reactions?

It is the Calvin cycle

[Aksa]

the last picture showing the calvin cycle, why is it 3 Co2 and 3 RuBP represented, i mean 6 co2 and 6 RuBP is required to produce 1 glucose right, and normal cycle is represented with 1 co2 and 1 rubp so why 3?

[Daria]

in the last question of calvin cycle…the diagram is showing the utilization of 6atp to convert ribulose 5- phosphate to RuBP but i think that there should be a utilization of 3 atp instead of 6…correct me if im wrong