Photosynthesis

Question 1

Light Dependant Reaction process

Answer 1

Chlorophyll molecule absorbs light energy, exciting a pair of electrons. Electrons leave chlorophyll causing photoionisation.
Excited electrons pass from electron carrier to electron carrier in thylakoid membrane. Electrons lose energy as each carrier is a lower energy level.
Energy is used to actively transport H+ ions through proton pump into thylakoid space
H+ ions move from high conc to low conc in stroma through ATPsynthase, allowing chemiosmosis
H+ ions and electrons reduce NADP
Photolysis provides electrons to replace one’s lost in photoionisation

Question 2

Light independent reaction process
(Calvin cycle)

Answer 2

Enzyme rubisco binds ribulose bisphosphate (5c) with CO2
Forms unstable 6 carbon intermediate
Breaks into 2X(3c) glycerine 3-phosphate (GP)
Energy from ATP and NADPH reduce GP into triose phosphate (3c)
1/6 of TP molecules produces organic molecules
5/6 of triose phosphate molecules used to reform back to RuBP, requires ATP

Question 3

Where does light indépendant reaction occur

Answer 3

Stroma

Question 4

Where does the light dependant reaction occur

Answer 4

thylakoid space and membrane

Question 5

What is chemiosmosis

Answer 5

Production of ATP using ATP synthase