A wide variety of organic compounds are used by living organisms.

a. ring with five carbons and one oxygen atom; 1 mark

b. $CH_2OH$ attached to C 5; 1 mark

c. OH and H attached by single bonds to C 1, C 2 and C 3 with OH facing upwards on C 2 and C 3; 1 mark

a. light (energy) absorbed by pigments/chlorophyll/photosystems; 1 mark

b. excited electrons passed to electron carriers/electron transport chain; 1 mark

c. protons/hydrogen ions pumped into thylakoid (space); 1 mark

d. proton gradient/high proton concentration generated; 1 mark

e. protons pass via ATP synthase to the stroma; 1 mark

f. ATP synthase phosphorylates ADP/ATP synthase converts ADP to ATP; 1 mark

g. photophosphorylation/chemiosmosis; 1 mark

ATP synthase/electron carriers/proton pumps/photosystems/pigment are in the thylakoid membrane;

a. translocation/movement by mass flow; 1 mark

b. in phloem sieve tubes; 1 mark

c. sieve plates/pores in end walls/lack of organelles allows flow (of sap); 1 mark

d. carbohydrates (principally) transported as sucrose; 1 mark

e. (sucrose/glucose/sugar/carbohydrate) loaded (into phloem) by active transport; 1 mark

f. loading/pumping in (of sugars) by companion cells; 1 mark

g. high solute concentration generated (at the source); 1 mark

h. water enters by osmosis (due to the high solute concentration); 1 mark

i. hydrostatic pressure increased/high hydrostatic pressure generated; 1 mark

j. pressure gradient causes flow (from source to sink); 1 mark

k. leaves are a source because carbohydrates are made there; 1 mark

l. transport to the sink where carbohydrates are used/stored; 1 mark