Chapter 11 photosynthesis

Question 1

Where does the light dependant reaction occur?

Answer 1

On the thylakoid membranes or grana.

Question 2

Where does the light independent reaction occur?

Answer 2

The stroma

Question 3

What happens in photoionisation of chlorophyll?

Answer 3

Light energy is absorbed by chlorphyll and that energy results in electrons becoming excited and raising up an energy level to leave chlorophyll.
Some of energy released from electrons is used to make ATP and reduced NAPD in chemiosmosis.

Question 4

What happens in chemiosmosis?

Answer 4

-Electrons that gained energy and left chlorophyll move along series of proteins embedded within thylakoid membrane.
-As they move along they release energy and some of the energy is used to actively transport or pump the protons from chloroplast stroma to thylakoid lumen.
-Electrochemical gradient is created
-Protons pass through the enzyme ATP synthase, which results in production of ATP.
-The protons combine with co-enzyme NADP to become reduced NADP. This is because the protons move from high to low conc gradient.

Question 6

Describe what happens during photoionisation in the light-dependent
reaction. (2)

Answer 6

1. Chlorophyll absorbs light
   OR
   Light excites/moves electrons in chlorophyll;
   Ignore photosystems.
2. Electron/s are lost
   OR
   (Chlorophyll) becomes positively charged;