Photosynthesis in Higher Plants Flashcards

1
Q

Green plants make their own food by the process of

A

Photosynthesis

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2
Q

A physicochemical process by which plants use light energy to drive the synthesis of organic compounds is called

A

Photosynthesis

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3
Q

The process which is primary source of all food on earth is

A

Photosynthesis

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4
Q

Apart from light and carbon dioxide, which pigment is essential for photosynthesis to occur?

A

Chlorophyll

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5
Q

A KOH soaked cotton will absorb gaseous _____________

A

Carbon dioxide

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6
Q

The scientist who in 1770 performed a series of experiments that revealed the essential role of air in the growth of green plants was

A

Joseph Priestley

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7
Q

Oxygen in 1774 was discovered by

A

Joseph Priestley

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8
Q

Who showed that sunlight is essential to the plant process?

A

Jan Ingenhousz

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9
Q

Ingenhousz in his experiment with an aquatic plant showed some bubbles formed around green parts of plant to be composed of

A

Oxygen

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10
Q

Only the green part of plants could release oxygen was proved by

A

Jan Ingenhousz

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11
Q

The scientist who provided evidence for production of glucose when plants grow was

A

Julius von Sachs

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12
Q

The scientist behind the finding that the glucose is made in green parts of plant and is usually stored as starch was

A

Julius von Sachs

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13
Q

Engelmann observed that bacteria accumulated mainly in region of ___________ and __________ light of split spectrum from his experiments on Cladophora

A

Blue and red

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14
Q

The first action spectrum of photosynthesis was described by

A

T. W. Engelmann

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15
Q

Cornelius van Niel based on his studies of purple and green bacteria, demonstrated that photosynthesis is essentially a _____________ reaction

A

Light dependent

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16
Q

Cornelius in his experiment demonstrated that in a light-dependent reaction, hydrogen from a suitable oxidisable compound reduces carbon dioxide to __________

A

Carbohydrates

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17
Q

Hydrogen donor for purple and green sulphur bacteria is

A

H2S

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18
Q

In purple and green sulphur bacteria, oxidation product is

A

Sulphur or sulphate

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19
Q

Cornelius inferred that oxygen evolved by green plant comes from ___________

A

Water

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20
Q

The cells of leaves having large number of chloroplasts are

A

Mesophyll cells

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21
Q

Within the chloroplast there is membranous system consisting of ________, the _________, and the ________ stroma.

A

Grana, stroma lamellae, matrix

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22
Q

Synthesis of sugar through enzyme reactions and its conversion to starch occurs in

A

Stroma

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23
Q

Reactions occuring in membrane system are called ___________ reactions

A

Light

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24
Q

Carbon reactions occuring in stroma are called

A

Dark reactions

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25
Q

Dark reactions are not directly dependent on light but on the products of light reactions like _______ and _______

A

ATP and NADPH

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26
Q

Separation of leaf pigments of any green plant can be done by which basic technique?

A

Paper chromatography

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27
Q

The four pigments giving colour to leaves are

A

Chlorophyll a, chlorophyll b, xanthophyll, carotenoids

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28
Q

The pigment which is bright or blue green in chromatogram is

A

Chlorophyll a

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29
Q

Colour of chlorophyll b in chromatogram is

A

Yellow green

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30
Q

Xanthophylls appear ____________ in chromatogram

A

Yellow

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31
Q

The colour range of carotenoids in chromatogram is

A

Yellow to yellow-orange

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32
Q

The substances that have an ability to absorb light, at specific wavelengths are called

A

Pigments

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33
Q

Maximum absorption of chlorophyll a occurs in ______and _______ regions

A

Blue, red

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34
Q

The chief pigment associated with photosynthesis is

A

Chlorophyll a

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35
Q

The three accessory pigments for light absorption in plants are

A

Chlorophyll b, xanthophylls and carotenoids

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36
Q

The function of accessory pigments is to absorb light and transfer the energy to __________

A

Chlorophyll a

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37
Q

Accessory pigments prevent __________________ of chlorophyll a

A

Photo-oxidation

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38
Q

Light absorption, water splitting, oxygen release, and the formation of high energy chemical intermediates are included in the process of _____________

A

Light reaction

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39
Q

High energy chemical intermediates formed during light reaction are

A

ATP and NADPH

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40
Q

The pigments are organised into two photochemical light harvesting complexes namely

A

PSI and PSII

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41
Q

In LHC, hundreds of pigments are bound to ________

A

Proteins

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42
Q

Each photosystem has all pigments except one molecule of _________ pigment.

A

Chlorophyll a

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43
Q

Each photosystem has all the pigments (except one molecule of chlorophyll a) forming a light harvesting system also called _______

A

antennae

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44
Q

Single chlorophyll a molecules forms

A

Reaction centre

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45
Q

n PSI, reaction centre chlorophyll a has an absorption peak at _______

A

700 nm

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46
Q

In PSII, reaction centre chlorophyll a has an absorption peak at _____

A

680 nm

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47
Q

PSI and PSII are also called _______ and ________ respectively

A

P700 and P680

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48
Q

In PSII, reaction centre chlorophyll a absorbs 680 nm wavelength of ______ light

A

Red

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49
Q

The excited electrons are picked up by an electron acceptor which passes them to _______________consisting of cytochromes.

A

Electron transport system

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50
Q

The movement of electrons in ETS is downhill in terms of which scale?

A

Redox potential scale

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51
Q

Electrons from ETS are passed on to pigments of which photosystem?

A

PSI

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52
Q

Electrons in reaction centre of PSI are excited when they receive red light of wavelength

A

700 nm

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53
Q

Electrons excited in PSI at 700 nm are transferred to another acceptor molecule that has higher __________

A

Redox potential

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54
Q

The whole scheme of transfer of electrons is referred to

A

Z scheme

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55
Q

Splitting of water is associated with which photosystem?

A

PS II

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56
Q

Electrons to replace those electrons removed from PSI are provided by

A

PSII

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57
Q

Electrons moved from PSII are replaced by electrons from ________

A

Splitting of water

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58
Q

PSII is located on

A

Inner side of thylakoid membrane

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59
Q

The process by which ATP is synthesised by cells is called

A

Phosphorylation

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60
Q

Phosphorylation occurs in which organelles?

A

Mitochondria and chloroplast

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61
Q

Synthesis of ATP from ADP and inorganic phosphate in the presence of light is called

A

Photophosphorylation

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62
Q

When the two photosystems work in a series, first PS II and then the PS I, then the process is called

A

Non-cyclic photophosphorylation

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63
Q

The products synthesised by non-cyclic photophosphorylation are

A

ATP and NADPH + H+

64
Q

When only PSI is functional, phosphorylation occurs due to

A

Cyclic flow of electrons

65
Q

Usually only PSI is functional in which part of chloroplast?

A

Stroma lamellae

66
Q

Membrane of stroma lamellae lack PSII as well as enzyme -

A

NADP reductase

67
Q

In stroma lamellae, excited electron instead of passing on to NADP+but is cycled back to

A

PSI complex

68
Q

Cyclic flow results only in synthesis of ________

A

ATP

69
Q

Cyclic photophosphorylation occursonly when light of wavelength beyond ______ nm are available for excitation.

A

680

70
Q

In photosynthesis, ATP synthesis is linked to development of ___________ across a membrane

A

Proton gradient

71
Q

ATP synthesis during photosynthesis occurs in the membrane of ______

A

Thylakoid

72
Q

During photosynthesis, protons accumulate in the lumen of _________

A

Thylakoid

73
Q

During photosynthesis, where does splitting of water molecules occur?

A

Inner side of thylakoid membrane

74
Q

Protons produced by splitting of water molecule are accumulated in ____________

A

Lumen of thylakoids

75
Q

During ATP synthesis, primary acceptor of electron transfers its electron to ___________

A

H carrier

76
Q

NADP reductase enzyme is located on the ____________

A

Stroma side of membrane

77
Q

Within chloroplast, protons in stroma decrease in number with decrease in pH of _________

A

Lumen

78
Q

Breakdown of proton gradient is crucial for synthesis of ____

A

ATP

79
Q

CF0of ATP synthase is embedded in _________

A

Thylakoid membrane

80
Q

The part of ATP synthase that carries out facilitated diffusion of protons across membrane is

A

CF0

81
Q

The portion of ATP synthase that protrudes on outer surface of thylakoid membrane on side towards stroma is

A

CF1

82
Q

Conformational change in _____ particle of ATP synthase induces synthesis of ATP

A

CF1

83
Q

Chemiosmosis requires a membrane, proton pump, ATP synthase and ___________

A

Proton gradient

84
Q

Diffusion of protons across membrane creates enough energy to activate ___________

A

ATP synthase

85
Q

Products of light reaction are -

A

ATP, NADPH and O2

86
Q

ATP and NADPH are used to drive processes leading to synthesis of ___________

A

Sugars

87
Q

Diffusion of O2out of chloroplast and use of ATP and NADPH to synthesise sugars are included in _______________ phase of photosynthesis

A

Biosynthetic

88
Q

Biosynthetic phase of photosynthesis is dependent on

A

Products of light reaction

89
Q

_____________ discovered that the first CO2fixation product was 3 carbon organic acid while working on algal photosynthesis

A

Melvin Calvin

90
Q

The first stable product of Calvin cycle was identified as

A

3-phosphoglyceric acid

91
Q

The 4 carbon product found as first stable product of CO2fixation in some plants was

A

Oxaloacetic acid

92
Q

The plants in which first stable product during CO2fixation was PGA were called

A

C3plants

93
Q

The pathway in which first stable product was found to be oxaloacetic acid was called

A

Hatch and Slack Pathway/ C4pathway

94
Q

The primary acceptor of CO2is a _____ carbon compound in C3 cycle.

A

5

95
Q

The primary acceptor of CO2that was a 5-carbon ketose sugar was found to be

A

Ribulose bisphosphate

96
Q

The photosynthetic pathway that occur in all types of plants is

A

C3

97
Q

The three main stages of Calvin cycle are

A

Carboxylation, reduction and regeneration

98
Q

The fixation of CO2into a stable organic intermediate is called

A

Carboxylation

99
Q

In C3 cycle during carboxylation, CO2is utilised for carboxylation of _________

A

RuBP

100
Q

The enzyme catalysing the reaction of carboxylation in calvin cycle is

A

RuBP carboxylase

101
Q

RuBP carboxylase catalyses the reaction of conversion of CO2to _______

A

PGA

102
Q

Enzyme involved in carboxylation is called

A

RuBisCO

103
Q

During reduction, series of reactions lead to the formation of ________

A

Glucose

104
Q

During reduction in C3cycle, how many molecules of ATP are required?

A

2

105
Q

2 ATPs during reduction in C3cycle are required for ________

A

Phosphorylation

106
Q

Synthesis of one molecule of glucose requires ______ turns of C3cycle

A

Six

107
Q

The number of CO2molecules fixed to form a molecule of glucose are

A

Six

108
Q

During regeneration phase of C3cycle, the molecule that needs to get regenerated is

A

RuBP

109
Q

Regeneration of RuBP requires how many ATPs for phosphorylation?

A

One

110
Q

For every CO2molecule entering C3cycle, _____ and ______ molecules of ATP and NADPH are required, respectively

A

3 and 2

111
Q

Six CO2molecule form one molecule of glucose in C3cycle is by utilising ____ ATPs.

A

18

112
Q

A molecule of glucose is synthesised by utilising ____ NADPHs

A

12

113
Q

CO2fixation in plants adapted to dry tropical regions occur by ___________

A

C4cycle

114
Q

C4plants use _____ pathway as the main biosynthetic pathway

A

C3

115
Q

Special leaf anatomy, tolerance to high temperatures, lack photorespiration are characteristic features of _______ plants

A

C4

116
Q

C4plants which show response to high light intensities and have greater productivity biomass have their first CO2fixation product as ____

A

OAA

117
Q

C4plants have special leaf anatomy called

A

Kranz anatomy

118
Q

The large cells around vascular bundles of C4plants are called

A

Bundle sheath cells

119
Q

Bundle sheath cells are characterized by having large number of

A

Chloroplasts

120
Q

The cells in C4plants which are imperveous to gaseous exchange and have no intercellular space are called

A

Bundle sheath cells

121
Q

Name two C4plants

A

Maize and sorghum

122
Q

The primary acceptor of CO2in Hatch and Slack pathway is

A

Phosphoenolpyruvate

123
Q

PEP in C4plants is present in

A

Mesophyll cells

124
Q

Enzyme responsible for fixation of CO2in C4cycle is

A

PEPcase or PEP carboxylase

125
Q

OAA is formed in

A

Mesophyll cells

126
Q

The enzyme which is not present in mesophyll cells of C4plants is

A

RuBisCO

127
Q

OAA before getting transported to bundle sheath cells gets converted into

A

Aspartic or malic acid

128
Q

C4acids in C4plants are broken down in ________________ to release CO2and 3C compound

A

Bundle sheath cells

129
Q

In C4 cycle, the 3-carbon molecule is transported back to the mesophyll where it
is converted to _______ again, thus, completing the cycle.

A

PEP

130
Q

Photosynthetic pathway which is common to all plants is ______

A

C3

131
Q

Bundle sheath cells of C4 plants are rich in enzyme -

A

RuBisCO

132
Q

Bundle sheath cells lack enzyme ________ which is present in mesophyll cells

A

PEPcase or PEP carboxylase

133
Q

Calvin pathway in C3plants occur in __________ while in C4plants, it takes place in _______

A

Mesophyll cells, bundle sheath cells

134
Q

During carboxylation, RuBP combines with CO2to form 2 molecules of _____

A

3-PGA

135
Q

The most abundant enzyme in the world is _______

A

RuBisCO

136
Q

RuBisCO has active sites both for _________ and _______

A

CO2and O2

137
Q

RuBisCO has greater affinity for _____ when CO2-O2ratio is equal

A

CO2

138
Q

What determines binding of CO2/O2to RuBisCO?

A

Relative concentration of CO2/O2

139
Q

O2binds to RuBisCO to produce?

A

Phosphoglycerate and phosphoglycolate

140
Q

Photorespiration is limited to ____ plants

A

C3

141
Q

When O2binds to RuBisCO instead of CO2, one molecule each of phosphoglycerate and phosphoglycolate are formed, this process is known as

A

Photorespiration

142
Q

The process that neither synthesizes sugar nor ATP and releases CO2on expense of ATP is

A

Photorespiration

143
Q

C4plants do not undergo photorespiration as they possess a mechanism that increases concentration of ____ at enzyme site

A

CO2

144
Q

If a chemical process is affected by more than one factor, then its rate will be determined by the factor which is nearest to its minimal value it is the factor which directly affects the process if its quantity is changed, is known as

A

Law of Limiting Factors

145
Q

Law of Limiting factors was given by

A

Blackman

146
Q

Incident light and CO2fixation rates at low intensity have _________ relationship

A

Linear

147
Q

Light saturation in plants occur at ___% of the full sunlight

A

10

148
Q

Increase in light beyond a point causes breakdown of ________

A

Chlorophyll

149
Q

The concentration of CO2 is very low in the atmosphere (between ____ and ____per cent).

A

0.03 to 0.04%

150
Q

CO2levels beyond _____% is damaging

A

0.05

151
Q

C4plants show CO2saturation at

A

360 µl/L

152
Q

C3plants show CO2saturationbeyond ___

A

450 µl/L

153
Q

Temperature has more effect on _________ reactions

A

Dark

154
Q

____ plants respond to higher temperature

A

C4

155
Q

Optimum temperature of a plant depends on its ________

A

Habitat

156
Q

Water stress causes the _______ to close hence reducing the CO2 availability.

A

stomata

157
Q

Water stress leads to ________ of leaves

A

Wilting