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Flashcards in 5.5 photosynthesis Deck (67)
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1

how is energy stored?

in glucose

2

where do animals take glucose from?

eating plants or other animals

3

where do plants take glucose from?

make it in photosynthesis

4

whats the photosynthesis equation?

6(CO2) + 6(H2O) = C6H1206 + 6(O2)

5

define respiration

cell releasing energy from glucose

6

what are the 2 types of respiration

anaerobic
aerobic

7

aerobic respiration equation

C6H12O6 + 6(O2) = 6(CO2) + 6(H2O)

8

which are the coenzymes used in photosynthesis?

NADP -transfers oxygen from one molecule to another (reduce/oxidise molecule)

9

coenzymes used in respiration

NAD/FAD -transfers hydrogen from one molecule to another (reduce/oxidise molecule)
coenzyme A - transfers acetate between molecules

10

chloroplast

-flattened structure in plant cells
-Double membrane
-inside contains thylakoid membrane stacked up into structures called grana linked together by bits of thylakoids, lamellae
-contain photosynthetic pigments
-contain stroma

11

which are the 3 photosynthetic pigments?

chlorophyll a
chlorophyll b
carotene

12

what are photosynthetic pigments?

coloured substances that absorb light energy

13

where are photosynthetic pigments found

chloroplast, thylakoids membrane attached to proteins

14

proteins + pigments =

photosystem

15

what does a photosystem contain?

2 types of photosynthetic pigments
-PRIMARY
-ACCESSORY

16

what is the role of primary photosynthetic pigment?

is the reaction centre
where electrons are excited in the light dependent reaction

17

what is the role of accessory photosynthetic pigment?

make up light-harvesting system, surrounds reaction centre and transfer light energy to them to excite electrons

18

how many photosystem are used to capture light energy?

2
- PI absorbs best at wavelength 700nm
- PII absorbs best at wavelength 680nm

19

what is stroma?

gel-like substances

20

where is stroma found?

surrounding thylakoids

21

what does stroma contain?

-enzymes
-sugars
-organic acids
-DNA (often circular), there can be multiple copies
-carbohydrates not used straight away (produced in photosynthesis) stored in starch grains

22

how many stages does photosynthesis have?

2
-light dependent reaction
-light independent reaction

23

where does LDR occur?

thylakoids membranes

24

describe LDR

-light energy absorbed by photosynthetic pigments in photosystem
-converted into chemical energy
-energy used to:
1. add an inorganic phosphate to ADP --> ATP (phosphorylation)
2. reduce NADP to form reduced NADP
3. split water into protons, electrons and oxygen (photolysis)
-H2O oxidises to O2

25

where does LIR occur?

stroma

26

describe LIR

- doesn't use light energy directly but relies on products
- ADP & reduced NADP supply energy and hydrogen to make glucose from CO2

27

experiment - to separate photosynthetic pigments

thin layer chromatography

28

two phases of thin layer chromatography

- mobile phase (liquid solvent)
- stationery phase (chromatography plate)

29

process of thin layer chromatography

1. grind leaves + anhydrous sodium sulfate + propanone = liquid
2. liquid + petroleum ether - test tube, shake - 2 layers, top one is pigments
3. top layer + anhydrous sodium sulfate - test tube
4. pencil line - bottom of chromatography plate, concentrates spot of liquid (several drops, dry) point of origin
5. plate in beaker with a solvent (line little above)
different pigments move at different rates, they will separate
6. when solvent nearly reached the top take out and mark solvent front and separated pigments (coloured spots)
7. calculate Rf values

30

Rf formule

distance travelled by spot / distance travelled by solvent