Adaptions of Chloroplast - Photosynthesis

Question 1

Chloroplast Envelope

Answer 1

Isolates reactions and prevents interference from other reactions e.g respiration.

Question 2

Envelope Membranes

Answer 2

Partially permeable so control entry of water and carbon dioxide, and exit of oxygen and glucose.

Question 3

Thylakoid Membranes of Grana

Answer 3

Site of light-dependent reaction, so have a large surface area for the attachment of the chlorophyll pigments/photosystem/electron carriers, allowing maximum light absorption.

Question 4

Stoma

Answer 4

Site of light-independent reaction/Calvin Cycle contains enzyme RuBP carboxylase (rubisco). It is aqueous so also allows diffusion of ATP and reduced NADP from the grana. Stroma contains insoluble storage products e.g starch grains and lipid droplets which have no effect on water potential of chloroplast.

Question 5

DNA and 70s Ribosomes

Answer 5

Allow DNA replication and protein synthesis to produce photosynthetic enzymes e.g dehydrogenases and decarboxylases.