Photosynthesis

Question 1

how are photosynthesis and respiration related

Answer 1

co2 and h20 are products for respiration and raw materials for photosynthesis
o2 and glucose are raw materials for respiration and products of photosynthesis

Question 2

describe the structure of a chloroplast

Answer 2

usually disc shaped
double membrane
thylakoids: flattened discs stacked to form grana
intergranal lamellae: tubular extensions attach thylakoids in adjacent grana stroma: fluid filled matrix with high enzyme and substrate concentration

Question 3

where does the light dependent reaction occur

Answer 3

thylakoid of chloroplast

Question 4

where does the light independent reaction occur

Answer 4

stroma of chloroplast

Question 5

what is the role of photosynthetic pigments

Answer 5

absorb different wavelengths to maximise rate of photosynthesis

Question 6

what are the two main groups of photosynthetic pigments

Answer 6

primary pigment: chlorophyll found in photosystems
accessory pigment: carotenoids found in light harvesting systems

Question 7

explain the role of light in photoionisation

Answer 7

chlorophyll molecules absorb energy from photons of light which excites 2 electrons (raising them to a higher energy level) causing them to be released from the chlorophyll

Question 8

what happens in the electron transport chain

Answer 8

electrons released from chlorophyll move down a series of carrier proteins in the thylakoid membrane and undergo redox reactions which releases energy

Question 9

how does chemiosmosis produce ATP

Answer 9

energy released from ETC causes active transport of H+ ions from stroma into thylakoid space
H+ ions diffuse down concentration gradient through specialised channel protein attached to ATP synthase
causes enzymes to turn and catalyse reaction of ADP to ATP