5.7 Photosynthesis

Question 1

Describe the structure of a chloroplast

Answer 1

• usually disc shaped
• double membrane (envelope)
• thylakoids: flattened discs that stack up to form grana
• intergranal lamellae: tubular extensions attcth thylakoids in adjacent grana
• stroma: fluid filled matrix high enzume and substrate concentration

Question 2

Desacribe the structure of chloroplasts in relation to their roles in photosynthesis

Answer 2

• The chloroplast is a membrane bound organelle so create a seperate environment (compartment) for photosynthetic reactions
• thylakoid (membranes) are the site of (light dependent reaction/photophosphorylation/chemiosmosis)
• idea that (thylakoid) membrane provide a space for accumulation of H+
• stroma is site of (light-independent reaction/calvin cycle/carbon fixation)

Question 3

Where do the light dependent and light indendependent reactions occur in plants?

Answer 3

• light-dependent: in the thylakoids of chloroplasts
• light-independent: stroma of chloroplasts

Question 4

What processes occur in the light dependent reaction?

Answer 4

-photoionisation
-electron transfer chain
-chemiosmosis
non-cyclic only:
-reduction of NADP
-photolysis of water