Directions: Each question below contains four suggested
Answers of which one or more is correct Choose the
Correct answer(s)
RESPIRATION
1. Dehydrogenase enzymes of the hexosemono-phosphate shunt pathway are
a. NAD+ specific
b. NADP+ specific
c. FAD specific
d. TPP specific
[JNU]
2. Which of the following processes does NOT involve
Cytochrome C?
a. oxidative phosphorylation
b. electron transport
c. TCA cycle
d. Apoptosis
[JNU]
3. Which of the following can serve as an inhibitor of
Electron transport?
a. puromycin
b. actinomycin D
c. malonate
d. cyanide
[JNU]
5. Uncoupling of oxidative phosphorylation implies that
a. the ATPase activity of mitochondria is abolished
b. the mitochondria ceases to oxidize succinate
c. ATP formation ceases but respiration continues
d. ATP formation continue but respiration ceases
[JNU]
7. Conversion of glucose to glucose-6-phosphate requires
ATP Yet; critically ill patients are given glucose solutions
Intravenously instead of glucose-6-phosphate. The
reason for not giving glucose-6-phosphate directly is
a. G-6 phosphate is degraded very fast in the blood
Before it enters the cells
b. commercial preparations of G-6 phosphate are
always contaminated with toxic chemicals
c. high cost of G-6 phosphate
d. cells cannot take up G-6 phosphate
[GATE]
11. NADH
Q
Cytb
Cytc1
Cytc
Cyt (a+a3)
O2
Sequence of electron transfer in oxidative
Phosphorylation in given above. Which of the
Following pair of inhibitors block the electron
Transfer in the steps marked with ?
a. rotenone and CO
b. antimycin-A and CO
c. antimycin-A and DCMU
d. DCMU and CO
[GATE]
12. Injection of dinitrophenol (DNP) into a rat causes an
Immediate increase in its body temperature because
a. DNP acts as an inhibitor of mitochondrial ATPase
b. DNP blocks the electron transport chain
c. DNP inhibits succinate dehydrogenase
d. DNP uncouples electron transport from oxidative
Phosphorylation
[GATE]
13. ATP synthetase is a multifunctional enzyme with a
Subunit constitution of α3β3γε. The pair of constituent
Subunit taking part in nucleotide binding and
Catalysis is
a. α1β1
b. α2β2
c. α3β3
d. γ
16. Which of the following enzyme-catalyzed reactions has
a product containing a newly formed high-energy
phosphate bond?
a. the phosphorylation of glucose
b. 2-phosphoglycerate to phosphoenolpyruvate
c. 3-phosphoglycerate to 2-phosphoglycerate
d. Phosphoenolypyruvate to pyruvate
17. The oxidation of 1 mol of glucose by anaerobic glycolysis
yields a net of
a. 2 mol of lactate and 2 mol of adenosine triphosphate
(ATP)
b. 2 mol of lactate, 2 mol of reduced nicotinamideAdenine dinucleotide (NADH), and 2 mol of ATP
c. 2 mol of lactate, 22 mol of NAD+, and 6 mol of ATP
d. 2 mol of pyruvate and 2 mol of ATP
19. The glycolytic pathway requires which of the following
As allosteric regulatory enzymes?
a. glucokinase, phosphofrutokinase, and pyruvate kinase
b. hexokinase, phosphofrutokinase, and pyruvate kinase
c. hexokinase, glyceraldehyde 3-phosphate dehydrogenase, and enolase
d. phosphofrutokinase, enolase, and pyruvate kinase
21. Glucokinase is characterized by which of the following
Statements?
a. it has a much higher Michaelis constant (Km) for
glucose than hexokinae
b. it phosphorylates most hexoses
c. it is an allosteric enzyme
d. it is found in most cells
22. Phosphofrutokinase is characterized by which of
the following statements?
a. it is a major regulatory enzyme in glycolysis
b. adenosine triphosphate (ATP) is a substrate of
the enzyme
c. ATP is a negative modulator of the enzyme
d. Citrate is a positive modulator of the enzyme
23. The function of the TCA cycle is characterized by all
of the following statements EXCEPT
a. it generates reduced nicotinamide-adenine
dinucleotide and reduced flavin-adenine
dinucleotide
b. it generates guanosine triphosphate
c. it catalyzes the complete oxidation of acetate
to carbon dioxide and water
d. it provides for the net synthesis of oxaloacetate
from acetyl CoA
26. Which of the reactions of the tricarboxylic acid cycle
Listed below results in the formation of a high-energy
Phosphate compounds?
a. isocitrate dehydrogenase
b. succinyl coenzyme A synthetase
c. succinate dehydrogenase
d. citrate synthetase
27. All of the enzymes of the TCA cycle are located in
the mitochondrial matrix EXCEPT for
a. citrate synthetase
b. α-ketoglutarate dehydrogenase
c. succinate dehydrogenase
d. fumarase
28. The initial step in the biosnthesis of ATP by
Chemiosmosis in the mitochondrion is the
a. accumulation of sufficient inorganic phosphate
by active transport
b. removal of phosphate from glucose-6-phosphate
c. pumping of protons into the outer compartment
d. pumping of electrons into the matrix
29. The release of carbon dioxide results from which of
The following reactions in th TCA cycle?
a. isocitrate to α-ketoglutarate
b. malate to oxaloacetate
c. α-ketoglutarate to succinyl coenzyme A
d. succinate to fumarate
33. All of the following electron carriers are components
Of the mitochondrial electron transport chain EXCEPT
a. nicotinamide-adenine dinucleotide
b. nicotinamide-adenine dinucleotide phosphate
c. flavin monocucleotide
d. flavin-adenine dinucleotide
36. Rotenone, which is used as a fish poison and as an
Insecticide, blocks mitochondrial electron transport by
a. inhibiting the interaction between oxygern and the
terminal electron carrier
b. inhibiting the reduction of cytochrome c
c. inhibiting the transfer of electrons through the NADH-CoQ reductase complex
d. inhibiting electron transfer at all nonheme iron-sulfur protein centers
37. Carbon monoxide inhibits mitochondrial electron
Transport by
a. binding to hemoglobin in the erythrocytes and so
blocking the transport of oxygen to tissues
b. binding to the oxygen-binding site of cytochrome
oxidase
c. blocking electron transport at the level of the
cytochrome b-cytochrome c1 complex
d. combining with coenzyme Q and preventing its
interaction with the nonheme iron-sulfur protein
center of complex II
38. The uncoupling of oxidative phosphorylation in a
mitochondrial system describes which of the
following actions?
a. the phosphorylation of adenosine diphosphate
(ADP) to adenosine triphosphate accelerates
b. the phosphorylation of ADP continues but
oxygen uptake stops
c. the phosphorylation of ADP stops but oxygen
uptake continues
d. oxygen uptake stops
39. If both oligomycin and 2,4-dinitrophenol are added to
A mitochondrial preparation in the presence of
Substrate, inorganic phosphate Mg2+, and
Adenosine diphosphate (ADP), then
a. both oxygen uptake and phosphorylation of
ADP would cease
b. oxygen uptake would be reduced, but
phosphorylation of ADP would continue
c. oxygen uptake would be high, but
phosphorylation of ADP would cease
d. none of the above
43. Which of the carbon atoms of pyruvate would be
Labeled during glycolysis of glucose having 14C at C-1?
a. carboxylate carbon
b. carbonyl carbon
c. methyl carbon
d. none
[GATE]
44. The formation of glucose in photochemical reactions
Involves the reduction of CO2 with the production of
O2. For this process which of the following agents
is responsible
a. FADH2
b. NADPH
c. ADP
d. none of the above
[GATE]
45. Which statement about oxidative phosphorylation is NOT true
a. the five assemblies of proteins and cofactors involved
include the electron transferring complexes I-IV and
ATP synthase
b. the mobile carrier ubiquinone links complexes I and II
with complex III and cytochrome C links complex III
with complex IV
c.for every two electrons transferred from NADH to Q
by complex I, two protons are translocated to the
intermembrane space.
d. FAD, FMN, iron-sulphur clusters and copper atoms
are other co-factors that participate in electron transfer
[GATE]
48. Ribose-5-phosphate is formed in the pentose phosphate
Pathway from
a. isomerization of ribulose-5-phosphate
b. reaction of fructose-6-phosphate and glyceraldehydes-3-phosphate
c. reaction of xylulose-5-phosphate and erythrose-4-phosphate
d. none of the above
51. The final electron acceptor in lactic acid fermentation
Is
a. NAD+
b. pyruvate
c. O2
d. lactic acid
53. Glycolysis has an efficiency level of approximately
a. 2%
b. 3.5 %
c. 21.5%
d. 50%
54. In aerobic cellular respiration, which generates more
ATP, substrate level phosphorylation or
chemiosmosis?
a. substrate level phosphorylation
b. chemiosmosis
c. both generate the same amount of ATP
d. neither generates any ATP
57. Glucose is metabolized through glycolysis and the
Krebs cycle. How do amino acids and fats get
Metabolized?
a. there are separate cycle can pathways for such
metabolism
b. they are broken down, modified, and fed into
various point in the same pathway as is used by
glucose
c. they are first converted to glucose molecules
d. only the amino group on the amino acids can be
used for energy, the rest is just degraded, while
fats are only stored
59. Which of the following statement is correct?
a. electron transport generates the proton motive force
b. peroxisomal oxidation of fatty acids generates no ATP
c. proton motive force in mitochondria is largely due to
voltage gradient across the membrane
d. total of 10H+ are translocated from the matrix across
the inner membrane per electron pair moving from
NADH to O2
60. Which of the following statement is incorrect?
a. during fermentation final electron acceptor is organic
compound
b. cardiolipin reduces the permeability of inner
mitochondrial membrane to protons
c. malate-asparate shuttle result in formation of 38 ATP
during aerobic respiration
d. PFK-2 catalyzes the formation of fructose 1,6
bisphosphate
63. Choose the correct statement
a. NADPH maintains the concentration of reduced
glutathione in RBC
b. G6PD deficiency is associated with resistance to
malaria
c. Wernicke-Korsakoff syndrome is associated with
disorder in HMP shunt
d. all
PHOTOSYNTHESIS
2. In Photosynthesis, the 1st step is
a. conversion of PG to PGA
b. carboxylation of RUBP
c. electron release by chlorophyll a
d. photolysis of water
3. In photorespiration, glycolate and glyoxylate are
Produced sequenctially in the following organelles.
Choose the correct sequence
a. chloroplast and mitochondria
b. chloroplast and peroxisome
c. peroxisome and mitochondria
d. peroxisome and chloroplast
[GATE]
4. In anoxygenic photosynthesis, the green and purple
Bacteria do not use the following one as electron
Source
a. H2O
b. H2
c. H2S
d. S(elemental sulphur)
[GATE]
6. Photooxidation of chlorophyll is prevented by
a. caroenoeid
b. anthocyanin
c. phycobilin
d. fucozanthin
[GATE]
7. For synthesis of one hexose sugar, for how many
Times Calvin cycle is turned?
a. 12
b. once
c. 6
d. 3
9. During photosynthesis, the final product of the Calvin
cycle is
a. ribulose bisphosphate
b. phosphoglycerate
c. pyruvate
d. glyceraldehyde-3-phosphate
[JNU]
10. Which of the following statements about cyclic
Photophosphorylation is not correct?
a. it does not lead to the synthesis of NADPH
b. it uses electrons supplied by photosystem II
c. it does not generate oxygen
d. it leads to pumping of protons via cytochrome bf
complex
[GATE]
12. Which of the following statements is correct with
Respect to the synthesis of starch and sucrose in
Plants?
a. starch is synthesized in the mitochondria and sucrose
in the cytosol
b. starch is synthesized in the cytosol and sucrose in the
chloroplast
c. starch is synthesized in the chloroplast and sucrose in
the mitochondria
d. starch is synthesized in the chloroplast and sucrose
in the cytosol
[JNU]
13. Among the following components of chloroplast
membranes, which one is the strongest reducing agent?
a. PQH2
b.Reduced cytochrome b6
c. Reduced ferredoxin
d.NADPH2
[JNU]
15. A carotenoid-less mutant plant was grown under
Normal sunlight, it will experience
a. increased photosynthetic rate
b.increased chlorophyll biosynthesis
c. reduced photorespiration
d.increased chlorophyll oxidation and necrosis
[JNU]
17. During photosynthesis, the protons created by the
Splitting of H2O
a. increases the concentration of H+ in the lumen
b. are transferred to photosystem I
c. freely dissipate through the thylakoid membrane
d. are pumped out by the b6-f complex to generate a proton gradient across the thylakoid membrane
18. During non-cyclic photophosphorylation, plants
And cyanobacteria produce
a. ATP
b. NADPH and H ion gradient
c. NADPH and ATP
d. NADH and ATP
[JNU]
21. Consider the following
1. cytochrome bc
2. cytochrome f
3. plastocyanin
4. plastoquinone
What is the equence of these in the photo-induced
Electron carriers between PSI to PSII in
photosynthesis?
22. The total requirement of ATP and NADPH for each
Molecule of CO2 fixed and reduced in photosynthesis in the Calvin cycle is
a. 2 ATP and 2 NADPH
b. 2 ATP and 3 NADPH
c. 3 ATP and 2 NADPH
d. 4 ATP and 3 NADPH
24. What is the strongest reducing agent in photoSynthetic electron-transfer reactions?
a. plastoquinone
b. P680*
c. P700*
d. P700
26. If the thylakoid are treated with detergent to stabilize
Lipids and then the proteins gently isolated, the
Following complexes will be observed, except
a. ATP synthase
b. Cytochrome oxidase
c. Light harvesting complex
d. Pheophytin
27. In the chemiosmotic hypothesis for energy generation
In chloroplast
a. electron transport carriers set up a proton gradient
b. a pH gradient drives the hydrolysis of ATP to ADP
c. ATP must be continually translocated into the
Chloroplast
d. electron transport carriers, use energy of moving
electron in uphill direction to form ATP
29. In chloroplast, PSI present on the
a. aperased membrane of the thylakoid
b. non-appearased membrane of the thylakoid
c. lumen of the thylakoid
d. inner membrane of chloroplast
31. C2 plants able to minimize photorespiration because
C4 plants
a. do not carry out the Calvin cycle
b. use a more efficient enzyme to initially fix CO2
c. exclude Calvin cycle
d. none
32. Photorespiration
a. occurs because oxygen rather than carbon dioxide
links to the rubisco enzyme in the Calvin cycle
b. occurs more in C4 than in C3 plants under identical
conditions
c. describes the up-take of carbon dioxide and the
release of oxygen in chloroplasts
d. all of the above
33. In non-cyclic light reactions of photsynthesis, electrons
from chlorophyll molecules in photosystem I are used in
the formation of NADPH. What is the source of such
electrons?
a. from light, which is converted directly into an electron
b. from ferredoxin
c. from mitochondria, which release the electrons at the end of the electron transport chain
d. from photosystem II, which splits water molecules
34. Which of the following incorporate CO2 into organic
Acids, and then release it for use in the Calvin cycle?
a. C3 plants
b. C4 plants only
c. C3 and CAM plants
d. C4 and CAM plants
35. Colors of light most useful in photosynthesis are
a. green, yellow and orange
b. red, violet and blue
c. infrared, red and yellow
d. red, white and blue
36. Which of the following is the correct sequence for the
Movement of electrons during the light-dependent
Reactions of plants?
a. P680 P700 water NADP+
b. Water P700 NADP+ P680
c. P700 P680 NADP+ water
d. Water P680 P700 NADP+
39. Photoexcited P680 and P700
a. have the same chemical properties of the ground
state molecules
b. are strond oxidants-taking electrons from donor
molecules
c. are strond reductants-giving electrons to acceptor
molecules
d. transfer excited state energy to another molecule
40. All of the following are false for non-cyclic electron
Transport in photosynthetic light membrane
a. the components of electron transport are arranged
asymmetrically across the thylakoid membrane
b. electrons flow from low energy water to reduce
high energy NADP+ due to absorption of photons
of light (by PSII and PSI) (PS stands for
photosystem)
c. electron transport establishes a proton gradient
across the thylakoid membrane
d. electron transport between PSII and PSI
produces ATP by substrate phosphorylation
43. When photosynthesis rate is plotted as a function of
Temperature, the graph will be
a. bell shape
b. sigmoid
c. straight line
d. none
44. At low CO2 concentration, photosynthesis is limited by
a. the carboxylation capacity of rubisco
b. ability of Calvin cycle enzyme to regenerate RuBP
c. ATP + NADPH
d. all
46. Synthesis of sucrose during photosynthesis occur at
a. chloroplast
b. cytosol
c. vacuoles
d. amyloplast
47. Total energy requirement for fixing one CO2 by combined
C4 and C3 cycyle is
a. 5 ATP + 4 NADPH
b. 3 ATP + 4 NADPH
c. 5 ATP + 2 NADPH
d. 8 ATP + 2 NADPH
49. Conversion of pyruvate into PEP by use of ATP in
C4 pathway occurs in
a. mesophyll cell’s cytoplasm
b. mesophyll cell’s chloroplast
c. bundle sheath cell’s cytoplasm
d. bundle sheath cell’s chloroplast
50. Which of the following plant species have highest
Photosynthetic rate?
a. species possessing CAM plants
b. species possessing C3 pathway
c. species possessing C4 pathway
d. same for all
52. Three molecules of RuBP in C3 cycle regenerated
from
a. 4 molecules of glyceraldehyde-3-phosphate
b. 5 molecule of 3-PGA
c. 5 molecules of glyceraldehyde-3-phosphate
d. 6 molecules of glyceraldehyde-3-phosphate
55. Electron carriers
a. pass electrons in an electron transport chain
from a more negative to a more positive reduction
potential
b. pass electons in an electron transport chain from
higher free energy to lower free energy
c. both
d. none
57. The two photosystem I and II during non-cyclic
Photophosphorylation acts in
a. parallel
b. series only
c. parallel and series only
d. none
58. Formation of ATP by ATP synthase present on
Thylakoid membrane occur during
a. down hill movement of H+ from thylakoid lumen
to stroma
b. down hill movement of H+ from stroma to
thylakoid lumen
c. up hill movement of H+ from stroma to
thylakoid lumen
d. up hill movement of H+ from thylakoid lumen
to stroma
59. Which of these statements about thioredoxin is
correct?
a. it contains a heme that cycles between two
oxidation states
b. its oxidized form predominates while light
absorption is taking place
c. it activates some biosynthetic enzymes by
reducing disulfide bridges
d. it activates some degradativ enzymes by
reducing disulfide bridges
62. Inhibition of photosynthesis in the presence of O2 in C3
Plants is called
a. Pasteur effect
b. Warburg effect
c. Decker effect
d. Hexose monophosphate shunt
66. The effect of herbicide, which blocks electron transport
From photosystem II to photosystem I will be result in
a. enhancement of dark reaction
b. failure to oxidize NADPH
c. lack of reduction of ferredoxin
d. both 2 and 3
67. Chloroplasts are disrupted and the stroma separated
From the lamellae. The isolated stroma will fix CO2 if
It is supplied with
a. oxygen
b. carotenoid
c. light
d. ATP + NADPH
71. Which of the following are true of C4 photoSynthesis
a. it seems to be advantageous in cooler climates
b. it has high compensation point for CO2
c. similar to the CAM photosynthesis pathway
d. all of the above
74. Consider the following events in photochemical
Reaction by chlorophyll during light reaction
1. charge separation
2. absorption of quantum of energy
3. ejection of election
4. transfer of light energy
a. 3, 2. 1. 3
b. 4, 2, 3, 1
c. 2, 4, 1, 3
d. 2, 4, 3, 1
75. When DCPIP (Hill reagent) accepts electron from
H2O, its colour changes to
a. blue
b. red
c. colourless
d. none
77. Oxygen evolving complex involved in photolysis of
Water contain
a. Mn2+, CI-, K+
b. Mg2+, CI-, Ca2+
2+
c. Mn , CI , CO
d. Mn2+, CI-, Ca2+
78. Which pigment will has higher absorbance in red region?
a. Chla
b. Chlb
c. both have same absorbance
d. carotene
80. Electrons in non-cyclic photophosphorylation moves from
a. a state of higher to lower free energy
b. more negative to a more positive reduction potential
c. both are correct
d. none
86. Consider the following pigments
1. Chl a
b. Chl b
3. Chl c
d. Carotene
5. Biliprotein
6. Xanthophyll
The characteristic photosynthesis pigments present
In chlorophyceae would include
a. 1, 2, 3, 4
b. 1, 3, 4, 5
c. 2, 3, 5, 6
d. 1, 2, 4, 6
91. If photosynthesizing green algae (oxygenic
photosynthesis) are provided with CO2 labelled
with an isotope of oxygen (18O that is “heavy” but NOT
radioactive), later analysis will show that all of the
following compounds produced by the algae contain
the 18O label EXCEPT
a. PGA
b. RuBP
c. glucose
d. O2
94. Which of the following statements best supports the
Fact that photorespiration, commonly occurs in C3 plants
a. C3 plants don’t possess Kranz anatomy
b. C3 plants have usually high CO2 compensation
species
c. C3 plants are less efficient in photosynthesis
d. C3 plants are characterized by RuBP oxygenase
activity under high oxygen supply
95. Which of the following compound in non-cyclic
Photophosphorylation in light reaction contains copper?
a. cytochrome
b. ferridoxin
c. plastoquinone
d. plastocyanin
97. Production of one molecule of 3-phospho-glyceraldehyde
Requires how many turns of the Calvin cycle?
a. 1
b. 2
c. 3
d. 6
98. Rubisco
a. catalyzes the carboxylation of CO2 to ribulose 1, 5bisphosphate
b. initiates photorespiration when the CO2/O2 ratio is
low
c. catalyzes the reduction of two molecules of PGAL to
form glucose
d. 1, 2 but not 3
100. Which statement about the light reactions of
Photosynthesis is FALSE?
a. electron from chlorophyll a are boosted to a
higher energy level
b. as electrons are lost from chlorophyll a and they
are replaced through the photolysis of water
c. the photolysis of water releases protons into the
interior of chloroplast membrane sacs (thylakoids),
thus generating a proton gradient that can drive
ATP synthesis
d. photophosphorylation resuls in the oxidation of
NADP+ to NADPH
102. Discovery of Emerson effect showed the existence
Of
a. photo respiration
b. light and dark reaction in photosynthesis
c. photophosphorylation
d. two distinct pigment systems
104. Photosynthetic yield will be more in
a. continuous red light
b. continuous blue light
c. intermitted white light
d. green light
106. The mechanism of ATP formation both in
Chloroplast and mitochondria is explained by
a. relay pump theory of Godlewski
b. cholodny went’s model
c. chemiosmotic theory
d. munch’s pressure/ mass flow model
107. Calvin cycle represent which of the following
Phenomenon
a. oxidative Carboxylation
b. substrate level phosphorylation
c. dark respiration
d. reductive carboxylation
110. In Carssulacean Acid Metabolism (CAM) plants
a. phosphoenolpyruvate carboxylase reduces CO2 to
make malic acid
b. stomata open only during the day
c. vascular tissue is surrounded by a bundle sheath
d. rubisco is activated only at night
111. Antenna pigments transfer light energy to a reaction
Center
a. by means of a process known as fluorescence
b. by means of a process known as inductive
resonance (direct transfer of energy)
c. by the conduction of heat
d. 1, 2 and 3 are all correct
117. PEP carboxylase is
a. involved in at least some CO2 fixation in both C3
and C4 plants
b. catalyzes the reaction fixing CO2 into pyruvic acid
in bundle sheath cells
c. capable of fixing CO2 more efficiently at lower
atmospheric CO2 concentrations than RuBP
carboxylase
d. the most abundant enzyme in the world
119. Which of the following is not a regulatory factor of
Carbon fixation
a. the level of acetyle-CoA in the chloroplast stroma
b. the levels of ATP and NADPH in the stroma
c. pH of the stroma
d. Mg++ level in the stroma
122. Photoinhibition
a. results in damage to proteins in the reaction
center
b. is less common in C3 plants relative to C4 plants
c. can result in the production of toxic oxygen
molecules
d. is the inhibition of photosynthesis due to the
absorption of excessive light energy
124. Cytochromes in cells are acceptor of
a. oxygen
b. H-ion
c. electron
d. CO2
125. C4 plants are abundant in
a. temperate region with more humid conditions
b. temperate region with more dry conditions
c. tropical region with more humid conditions
d. tropical region with more dry conditions