Photosynthesis (only key points so refer to notes)

Question 1

carbon fixation

Answer 1

carbon dioxide converted to organic compounds like sugars

Question 2

endothermic

Answer 2

needs energy

Question 3

reduction reaction

Answer 3

adding electrons

Question 4

exothermic

Answer 4

releases chemical energy

Question 5

photosynthesis

Answer 5

convert light energy into chemical energy

synthesise large organic molecules from simple inorganic molecules water and carbon dioxide

Question 6

respiration

Answer 6

oxidise organic molecules that have previously been synthesised to release chemical energy

Question 7

compensation point

Answer 7

not net gain or loss of carbohydrate

photosynthesis and respiration occur at same rate

Question 8

compensation period

Answer 8

time takes to reach compensation point

Question 9

light-dependent stage occurs in the

Answer 9

grana in thylakoids

Question 10

chloroplasts are how long?

Answer 10

2-10 μm

Question 11

light-independent stage occurs in the..

Answer 11

stroma

Question 12

what is the primary pigment reaction centre?

Answer 12

chlorophyll a

Question 13

accessory pigments

Answer 13

chlorophyll b, carotenoids, xanthophylls

Question 14

chlorphyll a P680

Answer 14

photosystem II

peak absorption 680nm wavelength

Question 15

chlorophyll a P700

Answer 15

photosystem I

peak absorption 700nm

Question 16

chlorophyll b absorbs

appears

Answer 16

400-500nm
around 640nm
yellow-green

Question 17

carotenoids

Answer 17

absorb blue 400-500nm

reflect yellow/orange

Question 18

xanthophylls

Answer 18

absorb blue and green 375-550nm

reflect yellow light

Question 19

photolysis

Answer 19

enzymes split water into protons (H), electrons, oxygen

in presence of light

Question 20

why is water useful?

Answer 20

source of protons used in photophosphorylation
donates electrons to chlorophyll so replace those lost when light strikes
source of by product oxygen
keeps cells turgid

Question 21

photophosphorylation

Answer 21

generation of ATP from ADP and inorganic phosphate

Question 22

non-cyclic photophosphorylation involves..

produces

Answer 22

PSI and PSII

ATP, oxygen, reduced NADP

Question 23

cyclic photophosphorylation involves..

produces

Answer 23

PSI

small quantity of ATP

Question 24

electron carrier

Answer 24

protein with iron at centre

in thylakoid membrane

Question 25

which products of the light-dependent stage does the light-independent stage use?

Answer 25

ATP

hydrogen

Question 26

RuBP

Answer 26

ribulose bisphosphate

Question 27

GP

Answer 27

glycerate-3-phosphate

Question 28

how many turns of Calvin cycle for 1 glucose?

Answer 28

6 turns for 2 TP for 1 glucose

Question 29

uses of TP

Answer 29

synthesise organic compounds:
glucose to sucrose/starch/cellulose
amino acids/fatty acids/glycerol
regenerate RuBP (10 TP for 6 RuBP)