PHOTOSYNTHESIS IN HIGHER PLANTS Flashcards

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1
Q

PHOTOSYNTHESIS

A

ANABOLIC ENDERGONIC OXIDO REDUCTION

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2
Q

EQUATION

A

6CO2 + 12H2O –> C6H12O6 + 6H2O + 6O2

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3
Q

% OF DRYMATTER FROM LAND

A

10

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4
Q

STARCH PRESENCE

A

BLUE - WITH IODINE

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5
Q

KOH USE?

A

ABSORBS THE CO2. USED IN THE EXP TO PROVE THAT CO2 IS NECESSARY FOR PHOTOSYNTHESIS ( MOLL HALF RKN)

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6
Q

PRIESTLY

A

1774 - DISCOVERED O2,
KILLED A MOUSE ( SUFFOCATION )
CANDLE EXTINGUISHED

USED MINT PLANT - MOUSE LIVES, CANDLE LIVES

PLANTS RESTORE THE AIR THE MOUSE AND CANDLE REMOVE

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7
Q

INGELHOUSZ

A

SUNLIGHT IS ESSENTIAL
- USED HYDRILLA
- NO BUBBLES IS FORMED (IN DARK)
- IN PRESENCE OF SUNLIGHT IT IS ONLY GREEN PARTS OF PLANT WHICH WILL RELASE O2

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8
Q

VON SACHS

A

GREEN PARTS - STARCH IS STORED ( CHLOROPHYLL)

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9
Q

ENGLEMANN

A
  • CLADOPHORA
  • SPECTRUM OF LIGHT + AEROBIC BACTERIA( TO DETECT PRESENCE OF O2 EVOLUTION)
  • BLUE AND RED LIGHT WAS THE HIGHEST
  • GREEN WAS LEAST
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10
Q

VAN NIEL

A

PURPLE AND GREEN SULPHUR BACTERIA
H2 RELEASED IS USED TO OXIDISE CO2 TO CH2O
- O2 IS FROM H2O AND NOT FROM CO2

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11
Q

RUBEN, KAMEN AND HASSID

A

USED NON RADIOACTIVE, STABLE ISOTOPE OF OXYGEN(O18)

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12
Q

PAR Full Form

A

PHOTOSYNTHETICALLY ACTIVE REGION

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13
Q

RANGE OF WAVELENGTH

A

400 - 700nm

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14
Q

Chlorophyll in the ?

A

mesophyll cells

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15
Q

thylakoids

A

third system of membranes in chloroplasts

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16
Q

granum

A

stack of thylakoids

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17
Q

grana is connected to another by

A

stroma lamallae

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18
Q

fluid compartment

A

stroma

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19
Q

stroma rkns

A

enzymatic rkn which synthesis sugar and convert to starch

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20
Q

CHLOROPHYLL-A

A

BLUE GREEN

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21
Q

CHLROPHYLL B

A

YELLOW GREEN

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22
Q

CARETOINDS

A

ORANGE YELLOW

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23
Q

XANTHOPHYLLS

A

YELLOW

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24
Q

CHLORPHYLL TWO PARTS

A

PORYPHRIN HEAD & PHYTOL TAIL, chlorphyll pigment looks like a tadpole

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25
Q

PORPHYRIN HEAD

A

HAS CYCLIC TETRAPHYROLIC STRUCTURE AND WITH NON IONIC MG ATOM

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26
Q

PHYTOL TAIL

A

HAS HYDROPHOBIC PORTION
TAIL ATTACHED TO RING STRUCTURE

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27
Q

ACCESORY PIGMENTS

A

ALL THE PIGMENT OTHER THAN CHLOROPHYLL A

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28
Q

why do chloroplasts align themselves vertically along the lateral walls of the mesophyll cells?

A

This is done under high light intensities so as to protect themselves from photo oxidation. this is also done to easily diffuse gases, and to receive optimum quantity of light.

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29
Q

absorbs the light of diff wavelength and transfer the energy to the chlorophyll molecules is called _________

A

antenna molecules

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30
Q

carotenoids protect the plant from heat and photo oxidn and so it is called _________

A

shield pigment

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31
Q

max photoysnthesis at ______

A

chlorphyll a

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32
Q

ps 1

A

P700
- found in the grana and stroma lamellae
- lies on the outer surface of thylakoids
- participates in cyclic and non cyclic flow of electrons
- no role in splitting of h20

33
Q

ps2

A

P680
- only grana lamellae
- inner surface of thylakoids
- only non cyclic flow of electrons
- splitting of h20

34
Q

complexes of harvesting molecules

A

LHC (Light Harvesting Complexes)

35
Q

ARNON

A

used assimalatory powers for nadph and atp. NADPH is reducing power

36
Q

photophosphylation

A

process of formation of ATP from ADP and inorganic phosphate ip utilising light energy

37
Q

ets

A

the process of reduction of NADP+ into NADPH and H+ is called ets

38
Q

redox potential

A

measure of tendency of chemical species to acquire e- and get reduced

39
Q

cyclic

A

only PS I is involved
- can happen only with light beyond 680 nm
- NADPH and H are not produced.
- synthesises ATP only
- operates under low intensity of light, anaerobic conditions, low co2
- occurs in stroma lamellae
- doesn’t take part in photosynthesis except in some bacteria

40
Q

non cyclic

A

PS I and II take part
- happens in granal thylakoids
- required an external e donor
- NADPH and H are produced
- takes place under optimum light, aerobic conditions
- connected with photolysis of water and liberation of oxygen occurs
- PASSES THRU ets of cytochromes

(NON CYLCIC ALSO CALLED AS Z SCHEME )

41
Q

who proposed z scheme

A

hill and bendall

42
Q

chemiosmotic hypothesis

A

explained by P Mitchell
explains how ATP is synthesised in the chloroplast and how it is linked to the development of a proton gradient across the membrane of the thylakoid

43
Q

what leads to development of proton gradient

A

Photolysis of water towards thylakoid lumen
2. Transfer of H from stroma to lumen as electrons move towards photosystems, via electron carriers
3. NADPH reductase happens towards the stroma and it requires H+
- decrease in ph of the lumen

44
Q

ATPase enzyme

A

this enzyme consists of two parts
1. CF0 this is embedded in the membrane and forms a transmembrane channel that carried out facilitated diffusion of protons across the membrane
2. CF1 this protrudes on the stroma side of the membrane

45
Q

REQUIREMENTS

A
  1. a proton pump which pumps protons across the membrane into the lumen
  2. ATPase enzyme which has CF0 part, which provides a transmembrane channel for facilitated diffusion of protons across the membrane
  3. Proton gradient
  4. A membrane.
46
Q

wHERE IS OEC LOCATED

A

INNER THYLAKOID

47
Q

OEC FUNCTION

A

OXYGEN EVOLVING COMPLEX HELPS IN SPLITTING OF H2O

48
Q

CALVIN CYCLE PROCESS

A

it is a five carbon ketose sugar called ribulose biphosphate or RuBP. The enzyme for CO2 fixation is ribulose biphosphate carboxylase oxygenase which can bind both CO2 and O2. It is the most abundant enzyme on earth. It has a higher affinity for CO2 than for O2. BE4 they discoverd rubisco they thought it would be 2 carbon compound since it was a c3 cycle

49
Q

diff process in c3 cycle

A
  1. Carboxylation- Rubisco catalyses the carboxylation of RuBP by CO2
  2. Reduction- formation of glucose
  3. Regeneration- regeneration of CO2 to continue the cycle

in- 18 ATP, 12 NADPH, 6 CO2
out- 18 ADP, 12 NADP, 1 glucose

50
Q

features of c4

A
  1. dry tropical plants
  2. special leaf anatomy - kranz
  3. can tolerate higher temperatures
  4. do not undergo photorespiration
  5. have bundle sheath cells
  6. can tolerate saline conditions due to the presence of organic acids which lowers their water potential
  7. can perform photosynthesis even when their stomata are closed due to presence of CO2 fixing enzyme pepcase
  8. concentric arrangement of cells in leaf produces a smaller area in relation to volume for better water usage
51
Q

bundle sheath

A
  1. have large number of chloroplasts
  2. have thick walls impervious to gaseous exchange
  3. no grana
  4. no intercellular spaces

this is called kranz anatomy, kranz means wreath

52
Q

c4 pathway also called

A

hatch slack pathway

53
Q

the plants in c4

A

sugarcane, maize, sorghum, amaranthus

54
Q

initial product

A

double fixation of co2 occurs
- 4 C compound - OAA formed in mesophyll converted to malic or asparatic in the mesophyll cell itself

55
Q

c4 process explanation

A

primary acceptor of co2 - PEP9 phosphoeol pyruvate) - mesophyll cells

56
Q

co2 fixation enzyme

A

PEPcase

57
Q

co2 is broken in

A

bundle sheath cells

58
Q

CO2 released undergoes

A

c3 cycle

59
Q

what does mesophyll and bundle sheath cells lack

A

mesophyll lacks rubisco and has PEPcase
bundle sheath lacks PEPcase and has abundant rubisco

60
Q

3 carbon compound formed in bundle sheath is transported to

A

mesophyll where they are converted to PEPcase by PEPsynthetase, regeneration requires 2 ATP

61
Q

atp consumed

A

2 in c4 cycle
3 in c3
total : 5 per co2

since 6 co2 is used so 30 ATP is consumed

62
Q

photorespiration

A

this is a process involving the loss of CO2 and is initiated in the chloroplasts
when there are high concentration of O2 rubisco acts as an oxygenase and binds to o2 so decreasing CO2 fixation. 1 molecule of PGA and phosphoglycolate(2C) is formed.
this results in the release of co2 with utlisation of ATP.(25% loss)
o2 is first utilized in chloroplast and then in the peroximes

63
Q

why doesnt it occur in c4

A

these plants have a mechanism which increases intracellular co2 concentration. when c4 acid is broken down in bundle sheath cells it realeases co2 forcing rubisco to act as a carboxylase.

64
Q

3 organelles involved in the c2 cycle or photorespiration

A

mitochondria - co2 is lost
chloroplast
peroximes

64
Q
A
65
Q

law of limitng factors

A

blackmann 1905
it states that

if a chemical process in affected by more than one factor, it’s rate will be determined by the factor that is closest to it’s minimal value.

66
Q

oxygenic photosynthesis

A

used as a source of reducing power in cyanobacteria. photolysis of water results in release of O2 as a by product and as it involves oxygen release it is called oxygenic.
example Oscillatoria

67
Q

anoxygneic photosynthesis

A

in bacteria evolution of oxygen has not been demonstrated as they can’t use water. they use H2S instead.

68
Q

carotenoids absorb which fractions of the visible spectrum of light?

A

violet and blue

69
Q

which is the first electron acceptor in PS I?

A

iron sulphur protein

70
Q

which complex of mitochondrial ETS possesses two copper centres?

A

complex 4

71
Q

The LHC are made up of hundreds of pigment molecules bound to ________

A

proteins

72
Q

how many molecules form the reaction centre

A

1 molecule of chloropjyll a

73
Q

In chemiosmosis, the primary acceptor of electron transfers its electron to?

A

H+ carrier

74
Q

By which transport method does the CF(0) of ATP Synthase carry protons back to stroma?

A

facilated diffusion

75
Q

How many molecules of PGA are produced upon the fixation of 1 molecule CO2?

A

2

76
Q

Plants of which region show C4 Pathway?

A

dry tropical

77
Q

Photosyntheic number?

A

also caled as assimalation number
- relation btw the chlorophyll and photosyntheis

78
Q

variagated leaves

A

croton