Lab 8

Question 1

weigh out – spinach

Answer 1

3g

Question 2

do not include – for spinach

Answer 2

large vascular tissue

Question 3

extract pigment should be bright green and – ml

Answer 3

25

Question 4

readings at 652 and 665 if you can’t get good readings the extract may need to be diluted up to –

Answer 4

10 fold

Question 5

gas pressure will arise in the stoppered funnel release pressure by inverting the funnel and then rotating until the upper layer contains all chlorophyll; turn the separatory funnel so the liquid is – the stopper end then slowly turn the vent

Answer 5

towards

Question 6

– is polar enough to dissolve less hydrophobic pigments

Answer 6

aqueous methanol

Question 7

separate chlorophyll and carotenoids of the petroleum ether layer by removing the – from the chlorophyll (resulting chlorophyllide or green chromophore is soluble in water)

Answer 7

hydrophobic phytyl tail

Question 8

– is caustic (burn or corrode organic tissue)

Answer 8

KOH

Question 9

vent the funnel – the hood

Answer 9

towards

Question 10

separate pigments in chlorophyll

Answer 10

thin layer chromatography

Question 11

each chlorophyll pigment has a different polarity so it moves at a different rate up a TLC plate through – when immersed in a solvent

Answer 11

capillary action

Question 12

TLC: – layer will be on top of chloroform and contains all the pigments in a concentrated form

Answer 12

hexane

Question 13

TLC: remove hexane layer without –

Answer 13

aqueous methanol

Question 14

hexane + pinch of – to get a concentrated solution of the pigments

Answer 14

anhydrous NaSO4

Question 15

allow solution to – between each spotting and minimize light exposure

Answer 15

evaporate

Question 16

keep TLC tank – or the solvent will evaporate

Answer 16

covered

Question 17

the level of petroleum ether: acetone must be – than the spot on paer

Answer 17

lower

Question 18

Rf = distance moved by – / distance moved by –

Answer 18

pigment/solvent

Question 19

slight differences in – of plates and in the solvent composition will affect the Rf values

Answer 19

dryness

Question 20

photosynthetic pigments are – located within proteins in the lipoprotein membranes (thylakoids) of chloroplast

Answer 20

lipids

Question 21

pigments can be extracted with – that dissolve the membrane lipids

Answer 21

organic solvents

Question 22

extracts = pigments involved in – + colorless lipids of lipid bilayer

Answer 22

photosynthetic light-harvesting apparatus

Question 23

molar ratio of a to b

Answer 23

3

Question 24

molar ratio of chlorophyll to carotenoids

Answer 24

5

Question 25

a and b have -- absorption spectra

Answer 25

similar

Question 26

carotenoids absorb in -- region

Answer 26

blue

Question 27

a have -- in the porphyrin ring while b has formyl group

Answer 27

methyl group

Question 28

methyl group makes a -- than b in nonpolar solvents

Answer 28

more soluble

Question 29

carotenoids have -- C atoms

Answer 29

40

Question 30

carotenes (orange) are pure --

Answer 30

hydrocarbonds

Question 31

xanthophylls (yellow) have -- than carotenes

Answer 31

oxygen atoms

Question 32

OH of xanthophylls make it -- than carotenes

Answer 32

less hydrophobic

Question 33

destroy pigments in vitro

Answer 33

light, heat extremes of pH and O2

Question 34

keep extracts cold and in the --

Answer 34

dark

Question 35

exclude light with

Answer 35

aluminum foil or black cloth

Question 36

KOH spill neutralized with --

Answer 36

vinegar

Question 37

point -- of funnel towards the hood when venting

Answer 37

end