Photosynthesis

Question 1

What is the process of light dependent reaction

Answer 1

Light energy absorbed by PSII which excities electron hence electron moves to higher energy level -> moves along electron transport chain in electron carrier molecules to PSI releasing energy as they go along which provides enough energy for H+ to be actively transported from stroma into thylakoid. The lost electron from PSII is replaced by photolysis of water (electron enters PSII). Once electron leaves PSI after light energy is absorbed by it, NADP accepts proton and electron forming reduced NADP and is carried into light independent reaction. Movement of H+ into thylakoid creates conc. gradient where H+ moves back down conc. gradient into the stroma via ATP synthase (produces ATP) ands this is transferred to LIR

Question 2

What occurs during calvin cycle

Answer 2

CO2 combines with RUBP via rubisco enzme to form unstable 6C intermediate which splits into 2x GP
2XGP is phosphorylsed via ATP 2x and is reduced 2x forming 2xTP and this is Phosphorylsed to form RUBP. RUBP comvines with CO2 and so on.

Question 3

What can TP be used as

Answer 3

Glucose
Amino Acids
Lipids

Question 4

Name a primary + accessory pigment

Answer 4

Primary -> Chlorophyll a
Secondary -> Chlorophyll b

Question 5

What is in a Photosystem

Answer 5

Light harvesting -> contains chlorphyll a + b
Reaction center -> only contaisn 2 chlorophyll a

Question 6

What do accessory pigments do

Answer 6

Transfer energy to primary pigments

Question 7

WHy does plant need more water with increased light intensity

Answer 7

Increases rate of transpiration - more ater vapour is lost
More stomata open to allow CO2 to enter