AQA BIOLOGY A LEVEL 7402 PAPER 1
ACTUAL EXAM PAPER COMPLETE
◉ What is the purpose of photosynthesis? Answer: To energy from
light is used to make glucose
◉ What is the general equation for photosynthesis? Answer: 6H2O +
6CO2 + energy --> C6H12O6 + 6O2
◉ What are the x stages of the light dependent reaction ? Answer: 1.
Photoionisation of PSII
2. Photolysis of water
3. Photoionisation of PSI
4. Active transport of H+ ions
5. Oxidative phosphorylation
6. Reducing NADP
◉ Describe what happens during photoionisation of PSII Answer:
Chlorophyll absorbs light
Electrons excited and move to higher energy level
Electrons move down electron transport chain to PSI
, ◉ Describe what happens during photolysis of water Answer: Light
energy splits water molecules into H+, e- and oxygen
The electrons replace those lost from PSII during photoionisation
◉ Explain how H+ ions are moved across the thylakoid membrane
Answer: The excited electrons from photoionisation lose energy as
they move down the electron transport chain
The energy is used to actively transport H+ into the chloroplast
◉ Explain how H+ are involved in the synthesis of ATP in
chloroplasts Answer: H+ move down their concentration gradient
into the stroma
This is via ATP synthase in the thylakoid membrane
The energy synthesises ATP from ADP and Pi
◉ Explain why the photoionisation of PSI is important Answer: The
excited eletrons are transferred to NADP with H+ to form reduced
NADP
This is needed for the light-independent reaction
◉ What is chemiosmosis ? Answer: Electrons move down the
electron transport chain and creating a proton gradient
This drived ATP synthesis
ACTUAL EXAM PAPER COMPLETE
◉ What is the purpose of photosynthesis? Answer: To energy from
light is used to make glucose
◉ What is the general equation for photosynthesis? Answer: 6H2O +
6CO2 + energy --> C6H12O6 + 6O2
◉ What are the x stages of the light dependent reaction ? Answer: 1.
Photoionisation of PSII
2. Photolysis of water
3. Photoionisation of PSI
4. Active transport of H+ ions
5. Oxidative phosphorylation
6. Reducing NADP
◉ Describe what happens during photoionisation of PSII Answer:
Chlorophyll absorbs light
Electrons excited and move to higher energy level
Electrons move down electron transport chain to PSI
, ◉ Describe what happens during photolysis of water Answer: Light
energy splits water molecules into H+, e- and oxygen
The electrons replace those lost from PSII during photoionisation
◉ Explain how H+ ions are moved across the thylakoid membrane
Answer: The excited electrons from photoionisation lose energy as
they move down the electron transport chain
The energy is used to actively transport H+ into the chloroplast
◉ Explain how H+ are involved in the synthesis of ATP in
chloroplasts Answer: H+ move down their concentration gradient
into the stroma
This is via ATP synthase in the thylakoid membrane
The energy synthesises ATP from ADP and Pi
◉ Explain why the photoionisation of PSI is important Answer: The
excited eletrons are transferred to NADP with H+ to form reduced
NADP
This is needed for the light-independent reaction
◉ What is chemiosmosis ? Answer: Electrons move down the
electron transport chain and creating a proton gradient
This drived ATP synthesis
