Energy for biological processes

Question 1

What photosystems are in non-cyclic phosphorylation?

Answer 1

One and two

Question 2

What wavelength of light does PS1 absorb?

Answer 2

700nm

Question 3

What wavelength of light does PS11 absorb?

Answer 3

680nm

Question 4

What are the stages of the light dependent stage?

Answer 4

Non-cyclic phosphorylation

Cyclic phosphorylation

Question 5

What are the stages of non-cyclic phosphorylation?

Answer 5

• Light energy excites electrons.
• Excited electrons are released from PS11 and pass to an ETC.
• ATP is produced by Chemiosmosis.
• Electrons lost from PS11 are replaced by the photolysis of water.
• Electrons are released fro PS1 and pass to another ETC.
• ATP is again produced by chemiosmosis.
• Electrons lost from PS1 are replaced by electrons that have just travelled along the first ETC.
• Electrons leaving the ETC after PS1 are accepted with a H ion by NADP which becomes reduced NADP.

Question 6

What is the centre of thylakoids called?

Answer 6

Lumen

Question 7

What are the products of the photolysis of light?

Answer 7

H ions, electrons and oxygen

Question 8

What happens in cyclic phosphorylation?

Answer 8

Electrons leaving the ETC after PS1 cab be returned to PS1. So ATP can be produced without electrons supplied from PS11. Reduced NADP is not produced.

Question 9

What is the photosystem in cylic phosphorylation?

Answer 9

1

Question 10

Where does the light dependent stage of photosynthesis occur?

Answer 10

Grana

Question 11

Where does the light independent stage of photosynthesis occur?

Answer 11

Stroma

Question 12

What are the products of the light-dependent reaction?

Answer 12

ATP and NADPH

Question 13

What are the products of the light-independent stage?

Answer 13

Lipids, glucose and amino acids

Question 14

What is needed for light dependent stage?

Answer 14

Water and light energy

Question 15

What is needed for light independent stage?

Answer 15

CO2 and products of the light dependent stage

Question 16

What are the steps of the Calvin cycle?

Answer 16

1) Carbon dioxide binds with RuBP (carbon is fixed/ incorporated into an organic molecule), catalysed by Rubisco.
2) RuBP breaks to form 2 GP.
3) GP is reduced to TP using a H from NADPH and energy from ATP.
4) Most TP is regenerated back to RuBP and some is the starting point for the synthesis for lipids, proteins and nucleic acids.