photosynthesis🌻

Question 1

describe how the light-dependent reaction results in the production of ATP

Answer 1

1. light is absorbed by the photosystems
2. exciting the pair of electrons out of the chlorophyll
3. the electrons move through the electron transport chain , releasing energy .
4. energy is used to actively transport protons across the thylakoid membrane .
5. protons diffuse back into the stroma via ATP synthase ( chemiosmosis)
6. this provides energy for ATP synthase to catalyse ADP an pi into ATP

Question 2

The production of glucose from the light independent ( Calvin cycle ) will drop significantly when a plant is left in the dark

Answer 2

1. light independent reaction requires products of the light dependent reaction like ATP that is produced in the light dependent
2. ATP is needed to regenerate RuBP
3. Reduced NADP is needed to convert GP into TP

Question 3

Role of ATP in the light-independent reaction

Answer 3

• Provides energy for the regeneration of RuBP
• Provides the energy to convert GP to TP

Question 4

Role of NADPH in the light-independent reaction

Answer 4

Provides the H+ ions for the conversion of GP to TP

Question 5

The role of water in the light-dependent reaction

Answer 5

1. photolysis of water - split into electrons, protons and oxygen
2. provides electrons that are lost from photoionisation
3. provides protons to maintain high concentration in thylakoid space