Photosynthesis

Question 1

Electrons in light dependent reaction

Answer 1

Light enters photosystem in thylakoid membrane, absorbed by chlorophyll, excites an electron, electron leaves chlorophyll molecule, travels down electron transport chain, energy is used by ATP to syntesise ATP.

Question 2

What happens to water during photosynthesis

Answer 2

Photolysis, water molecule lysed with light. Products: electron, H+ ions, oxygen. Electron replaces excited one in chlorophyll.

Question 3

How ATP is synthesised

Answer 3

Energy from electrons used to actively transport H+ ions out of thylakoid membrane. H+ ions diffuse back into thylakoid through ATP synthase. KE from H+ used to combine ADP and Pi+

Question 4

How NADP is reduced

Answer 4

Light absorbed by photosystem excites electron, electron and H+ ion used to reduce NADP

Question 5

Cyclic photophosphorylation

Answer 5

Electrons are passed back to chlorophyll

Question 6

Light independent reaction/Calvin cycle

Answer 6

CO2 combines with RuBP (enzyme rubisco), forms unstable 6C compounds, splits to 2 GP, hydrolysis of 2 ATP and 2 NADPH for 2 TP. TP used to make complex molecules such as: sucrose, glucose and cellulose.

Question 7

How many cycles does it take to make 1 hexose sugar

Answer 7

6 cycles, 5 TP molecules used resynthsesise RuBP