Practice Paper 2

1. All are true about glutathione except:

A. Converts hemoglobin to methemoglobin

B. Decreases free radicals

C. Helps in conjugation

D. Cofactor of various enzymes.

2. A promoter site on DNA:

A. Codes for RNA polymerase

B. Initiates transcription

C. Regulates termination

D. Transcribes repressor

3. Guanosine triphosphate (GTP) is required by which of the following steps in protein synthesis?

A. Aminoacyl-tRNA synthetase activation of amino acids

B. Attachment of ribosomes to endoplasmic reticulum

C. Translocation of tRNA-nascent protein complex from A to P sites

D. Attachment of mRNA to ribosomes

4. In the Lineweaver-Burk plot,  the Vmax of an enzyme is:

A. Reciprocal of the absolute value of the intercept of the curve with the x axis

B. Reciprocal of the absolute value of the intercept of the curve with the y axis

C. Absolute value of the intercept of the curve with the x axis

D. Slope of the curve.

5. In which of the following type of hyperlipoproteinemias, both LDL and VLDL is raised.

A. Type III                     B. Type IIa

C. Type IIb                    D. Type V

6.  Blood spills on the floor are cleaned by

A. Sodium hypochlorite

B. Iodine

C. Alcohol

D. Quaternary ammonium compounds

107. After a meal, blood glucose enters cells and is stored as glycogen, particularly in the liver. Which of the following is the donor of new glucose molecules in glycogen?

A. UDP-glucose-1 phosphate

B. UDP-glucose

C. UDP-glucose-6-phosphate

D. Glucose -6- phosphate

8. The problem of regenerating NAD+ from NADH for cytoplasmic processes by using mitochondria is solved in the most energy-efficient manner by which one of the following intercellular shuttle systems?

A. Citrate à pyruvate shuttle

B. Dihydroxyacetone phosphate à a-glycerophosphate shuttle

C. Malate à citrate shuttle

D. Citrate à citrate shuttle

9. Which of the following Hyperlipoproteinemia do not increase the risk of coronary atherosclerosis?

A. Type I                       B. Type II

C. Type III                     D. Type IV


10. The reactions of the urea cycle occurs in which one of the following?

A. In the cytosol

B. In lysosomes

C. In the mitochondrial matrix

D. In the mitochondrial matrix and the cytosol

11. Biotin is involved in which of the following types of reactions?

A. Hydroxylations          B. Carboxylations

C. Decarboxylations      D. Dehydrations

12.  Glowing of Firefly is due to:

A. ATP              B. NADH

C. GTP             D. Phosphocreatine

13. Which of the following statements about prostaglandins is true?

A. They are precursors to arachindonic acid

B. They release arachidonic acid from membranes through the action of phospholipase A

C. They were first observed to cause uterine contraction and lowering of blood pressure.

D. Although found in many organs, they are synthesized only in the prostate and seminal vesicles

14. A child with cleft palate, a heart defect, and extra fifth fingers is found to have 46 chromosomes with extra material on one homologue of the chromosome 5 pair. This chromosomal abnormality is best described by which of the following terms?

A. Polyploidy

B. Balanced rearrangement

C. Ring formation

D. Unbalanced rearrangement

15. Patient with hereditary nonpolyposis colon cancer have genes with microsatellite instability, that is, many regions containing abnormal, small loops of unpaired DNA. This is a result of a mutation affecting.

A. Mismatch repair        B. Chain break repair

C. Base excision repair  D. Depurination repair

16. The highest concentration of cystine can be found is which of the following?

A. Chondroitin sulfate

B. Collagen

C. Keratin                     

D. Melanin

17. Which of the following is not an essential amino acid?

A. Lysine

B. Threonine

C. Isoleucine

D. Arginine

18. In the study of evolution we see that the protein sequence is different but the shape of protein is same, this is known as

A. Convergent

B. Divergent

C. Opportunistic

D. Drift

19. The specific activity of an enzyme would be reported in which of the following units of measure?

A. Micromoles per minute

B. Milligrams per micromole

C. Millimoles per liter

D. Units of activity per milligram of protein

20. Gene for folic acid absorption is present on: 

A. Chromosome X

B. Chromosome XXI

C. Chromosome V

D. Chromosome XI

21. A new born begins vomiting after feeding, becomes severely jaundiced, and has liver disease. Treatment for possible sepsis is initiated, and the urine is found to have reducing substances. A blood screen for galactosemia is positive, and lactose-containing substances are removed from the diet. Lactose is toxic in this case because of which of the following?

A. Excess glucose accumulates in the blood

B. Galactose is converted to the toxic substance galactitol

C. Galactose competes for glucose during hepatic glycogen synthesis

D. Galactose is itself toxic in even small amounts

22. Dehydrogenases serve two main functions: (1) transfer of H+ from one substrate to another in a coupled oxidation-reduction reaction; and (2) they serve as components in the respiratory chain of electron transport. Dehydrogenases can use which of the following compounds as an electron acceptor?

A. H2O                         


C. O2

D. Peroxide

23. An adolescent female develops hemiballismus after anesthesia for a routine operation. She is tall and lanky, and it is noted that she and her sister both had previous operations for dislocated lenses of the eyes. The symptoms are suspicious for the disease homocystinuria. Which of the following statements is descriptive of this disease?

A. Patients may be treated with dietary supplements of vitamin B12

B. Patients may be treated with dietary supplements of vitamin C

C. There is deficient excretion of homocysteine

D. There is a defect in the ability to form cystathionine from homocysteine and serine

24.  Which one of the following transfers acyl groups?

A. Thiamine pyrophosphate

B. Lipoamide



25. Which of the following hormones can cause hyperglycemia without known effects on glycogen or gluconeogenesis?

A. Thyroxine

B. Epinephrine

C. Glucocorticoids

D. Epidermal growth factor

26. Ectrodactyly is an autosomal dominant trait that causes missing middle fingers (lobster claw malformation). A grandfather and grandson both have ectrodactyly, but the intervening father has normal hands by x-ray. Which of the following terms applies to this family?

A. Incomplete penetrance

B. New mutation

C. Variable expressivity

D. Germinal mosaicism

27. The replication fork consists of four components. Which of the following components is responsible for synthesis of the short RNA molecules essential for DNA replication?

A. Helicase

B. Primase

C. Polymerase


28. True about Linkage Studies is

A. Characteristic DNA polymorphism in a family is associated with disorder

B. Used to make pedigree chart to show affected and non affected family members

C. Used to make pedigree charts to show non paternity

D. Links diseases with families

29. Which of the following types of mutations generally leads to a truncated protein?

A. Deletion

B. Frameshift mutation

C. Insertion

D. Missense mutation

30. Which of the following amino acid is only glucogenic not ketogenic.

A. Tyrosine

B. Tryptophan

C. Threonine

D.  Isoleucine

31. The End Codon of t-RNA at poly (A) “tail” codes for?

A. Poly alanine

B. Poly proline

C. Poly lysine

D. Poly glycine

32. Which two amino acids are most commonly found in b turns in proteins?

A. Arginine and lysine

B. Aspartic acid and glutamic acid

C. Leucine and valine

D. Glycine and proline

33. In COPD there is chronic hypoxia that is particularly obvious in vascular tissues such as the lips or nail beds (cyanosis). Poorly perfused areas exposed to chronic hypoxia have decreased metabolic energy for tissue maintenance and repair. Which of the following is an important reason for this?

A. Increased hexokinase activity owing to increased oxidative phosphorylation

B. Increased ethanol formation form pyruvate on changing from anaerobic to aerobic metabolism

C. Increased glucose utilization via the pentose phosphate pathway on changing from anaerobic to aerobic metabolism

D. Decreased ATP generation and increased glucose utilization on changing from aerobic to anaerobic metabolism.

34. Which of the following is not a part of coenzyme complex in nitric oxide synthesis?




D.  Biotin


35. Dopamine hydroxylase converts dopamine to norepinephrine. The vitamin used as a cofactor in this reaction is:

(A) A      (B) C    (C) B 12         (D) D

36. Lipogenesis occurs in which cellular compartment

A. Cytosol

B. Endoplasmic reticulum

C. Golgi body

D. Mitochondria

37. Which is the rate-controlling step of pyrimidine synthesis that exhibits allosteric inhibition by cytidine triphosphate (CTP)

A. Aspartate transcarbamoylase

B. Hypoxanthine-guanine phosphoribosyl transferase (HGPRT)

C. Thymidylate synthase

D. Ribose-phosphate pyrophosphokinase

38. During starvation, which of the following shows the most marked increase in plasma concentration?

A. Free fatty acids

B. Glucose

C. Glycogen

D. Ketone bodies


39. Blue-white Color Screen technique is Used In DNA Cloning For?

A. To detect host DNA

B. To Screen for recombinant vectors

C. To find out the new cloned fragment of DNA

D. To find out the plasmid incorporated in DNA

40. Which of the following is helpful in transport of fructose in Sperm?





41. Which of the following descriptions of DNA replication is not common to the synthesis of both leading and lagging strands?

A. RNA primer is synthesized

B. DNA polymerase III synthesizes DNA

C. Helicase (rep protein) continuously unwinds duplex DNA at the replication fork during synthesis

D. DNA ligase repeatedly joints the ends of DNA along the growing strand

42. Studies of the genetic code in bacteria have revealed that:

A. Gene sequence and encoded proteins are not collinear

B. Messenger RNA (mRNA) molecules specify only one polypeptide chain

C. Many triplets can be “nonsense” triplets

D. No signal exists to indicate the end of one codon and the beginning of another.

43. Which of the following hormone acts via IP3 /DAG as second messenger?

A. Adrenaline

B. Glucagon

C. Vasopressin

D. Calcitonin

44. The substitution of valine for glutamate at position 6 on the two b chains in sickle cell hemoglobin causes which of the following?

A. Decreased polymerization of deoxyhemoglobin

B. Increased electrophoretic mobility at pH 7.0

C. Increased solubility of deoxyhemoglobin

D. More flexible RBCs

45. Mr Ramesh 25 years, flushes and feel ill after drinking small amounts of ethanol in alcoholic beverages. This reaction is due to genetic variation in an enzyme that metabolizes the liver metabolite of alcohol, which is:

A. Methanol

B. Acetone

C. Acetaldehyde

D. Hydrogen peroxide

46. Which of the following is not a phase II metabolism reaction:

A. Sulfation

B. Acetylation

C. Carboxylation

D. Methylation

47. Why is the yield of ATP from the complete oxidation of glucose lower in muscle and brain than in kidney, liver, and heart?

A. Different shuttle mechanisms operate to transfer electrons from the cytosol to the mitochondria in the two sets of tissues

B. Muscle and brain cells have a lower requirement for ATP

C. There are fewer mitochondria in muscle and brain cells

D. There are fewer ATP syntheses in muscle and brain cells

48. Which of the following is not a method of protein purification?

A. Electrophoresis

B. Ultracentrifugation

C. Densitometry

D. Chromatography

49. Most of the reducing equivalents utilized for synthesis of fatty acids can be generated from:

A. The pentose phosphate pathway

B. Glycolysis

C. The citric acid cycle

D. Mitochondrial malate dehydrogenase

50. Which of the following vitamins can act without phosphorylation?

A. Pyridoxine

B. Lipoamide

C. Niacin

D. Thiamine

51. Which of the following statements correctly describes insulin?

A. It is an anabolic signal to cells that glucose is scarce

B. It is converted from proinsulin to insulin primarily following secretion from beta cells

C. It does not have a prohormone form

D. Its action is antagonistic to that of glucagon

52. Which one of the following products of protein metabolism is decreased below normal levels during the early stages of starvation?

A. Urea

B. Anabolic enzymes

C. CO2                           

D. Nh4+

53. Autosomal recessive conditions are correctly characterized by which of the following statements?

A. They are often associated with deficient enzyme activity

B. Both alleles contain the same mutation

C. They are more variable than autosomal dominant conditions

D. Most persons do not carry any abnormal recessive genes

54. DNA sequencing by the Sanger method takes advantage of which property of DNA synthesis to generate a sequencing ladder?

A. Addition of nucleotides requires a free 01-I group on the 3’ end of the DNA strand

B. DNA has a free 5’ phosphoryl group

C. DNA polymerase has proofreading capabilities

D. Nucleotides are linked by phosphodiester bonds

55. In which  of the following disease patient is not photosensitive?

A. Acute intermittent porphyria

B. Variegate porphyria

C. Porphyria cutanea tarda

D. Erythropoietic Protoporphyria

56. The hydrolytic step leading to the release of a polypeptide chain from a ribosome is catalyzed by which of the following?

A. Dissociation of ribosomes

B. Peptidyl transferase

C. Release factors

D. Stop codons

57. The chemotherapy drug fluorouracil undergoes a series of chemical changes in vivo that result in a covalent complex such that it is bound to both thymidylate synthase and methylene-tetrahydrofolate. The inhibition of deoxythymidylate formation and subsequent blockage of cell division is due to which of the following?

A. Allosteric inhibition

B. Competitive inhibition

C. Irreversible inhibition

D. Noncovalent inhibition

58. Which compound is recycled in the citric acid cycle and thus serves a catalytic role?

A. Acetyl-CoA

B. Citrate

C. Oxaloacetate

D. Succinate

59. Which of the following regulates lipolysis in adipocytes?

A. Activation of fatty acid synthesis mediated by cyclic AMP

B. Activation of triglyceride lipase as a result of hormone-stimulated increases in cyclic AMP levels

C. Glycerol phosphorylation to prevent futile esterification of fatty acids

D. Activation of cyclic AMP production by insulin

60. Pyrrole rings of hemoglobin molecule is attached to iron by:

A. His E 7


C. NH2

D. Guanidino group

61. The demyelinating disease multiple sclerosis is characterized by a loss of which lipids?

A. Phospholipids and ceramide

B. Sphingolipids and ceramide

C. Sphingolipids and gangliosides

D. Phospholipids and sphingolipids

62. Fully activated pyruvate carboxylase depends on the presence of which of the following substances?

A. Malate and niacin

B. Acetyl-CoA and biotin

C. Acetyl-CoA and thiamine pyrophosphate

D. Oxaloacetate and biotin

63. Hemoglobin electrophoresis is based on

A. Molecular weight

B. Charge and mobility

C. Solubility

D. Calorimetric properties

64. Which of the following vitamins becomes a major electron acceptor, aiding in the oxidation of numerous substrates?

A. Vitamin B6                                

B. Niacin

C. Riboflavin

D. Thiamine

65. Which of the following processes yields arachidonic acid in mammals?

A. Elongation of stearic acid

B. Chain elongation and one desaturation of linolenic acid

C. Chain elongation and two desaturations of linoleic acid

D. Desaturation of oleic acid

66. Which of the following amino acid level not increase in Maple syrup urine disease:

A. Methionine                B. Leucine

C. Isoleucine                 D. Valine

67. All are true about translation in eukaryotes except 

A. The mRNA is translated from 5′ to 3′ end

B. 1st amino acid is formylated

C. Capping at 5′ end in mRNA is helpful in recognitiony translatory mechanism

D. It requires GTP to GDP transformation

68. How many high –energy  phosphate-bond equivalents  are utilized in the process of activation of amino acids for protein synthesis ?

A. Four             B. One

C. Two              D. Three

69. Modification of mRNA so that a signal sequence is added to the amino terminus of  the  process of activation of amino acids for protein synthesis ?

A. No change in physiology of the protein

B. Cytosolic localization of the protein

C. Signal recognition particle synthesis

D. Translocation across the endoplasmic reticulum


70. A 54-yrs old man with type I diabetes  is suffered to an ophthalmologist for evaluation of developing  cataract. Which of the following enzymes is most  strongly associated with cataract formation in this patient.

A. Glucokinase

B.  Aldose reductase

C. Sorbitol dehydrogenase

D. Sorbitol reductase

71. “Zinc fingers” serve as binding sites for hormones that:

A. Act rapidly

B. Effect cAMP levels

C. Liberate diacylglycerol

D. Alter transcription rates

72. Which of the following is responsible for oxygen dependant killing?

A. Glutathione peroxidase

B. NADPH oxidase

C. Catalase

D. Superoxide dismutase

73. After alcohol ingestion, which of the following intermediates accumulates in liver that is not typical of glycolysis or the citric acid cycle ?

A. Acetyl – CoA             B. Lactate

C. Acetaldehyde            D. Citrate

74. Which of the following enzymes allows the high-energy phosphate of ADP to be used in the synthesis of ATP?

A. Adenylyl kinase

B. ATPase

C. Inorganic pyrophosphatase

D. Nucleoside diphosphate kinase

75. Which of the following is the major source of extracellular cholesterol?

A. Very-low-density lipoproteins (VLDLs)

B. Low –density lipoproteins (LDLs)

C. High –density lipoprotein (HDLs)

D. Albumin

76. Which one of the following cofactors must be utilized during the conversion of acetyl-CoA to manloyl-CoA ?

A. Thiamine pyrophosphate

B. Acyl carrier protein(ACP)

C. Biotin


77. Glucose has four asymmetric carbons and can form sixteen isomers. Which of the following is a ketose isomer of glucose?

A. Fructose                  

B. Galactose

C. Glucofuranose

D. Glucopyranose

78. A couple is referred to the physician because their first three pregnancies have ended in spontaneous abortion. Chromosomal analysis  reveals that the wife  has two cell lines  in her blood, one with a missing  X  chromosome (45,X) and the other normal (46,XX). Her chromosomal constitution can be described as ?

A. Chimeric       B. Monoploid

C. Trisomic       D. Mosaic 


79. Which of the  following genetic disorders has a similar incidence in different ethnic groups ?

A. Cystic fibrosis                      B. Thalassemias

C. Tay-Sachs disease                D. Down’s syndrome


80. TRUE regarding main function of Apoprotein C

A. Cholesterol synthesis

B. TG transport

C. Increases activity of lipoprotein lipase

D. Fatty acid synthesis

81. Deficiency of which enzyme results in Krabbe’s disease?

A. Alpha-galactosidase

B. Beta-Glucosidase

C. Beta Galactosidase

D. Ceramidase

82. A male child presents with delayed development and scarring of the lips and hands . His parent have restrained him because he obsessively chews on his lips and fingers which of the following is likely to occur in this child?

A. Increased levels of 5- phosphoribosyl – 1    pyrophosphate (PRPP)

B. Decreased purine synthesis.

C. Decreased levels of uric acid.

D. Glycogen storage.

83. Which one of the following statement is correct regarding the well fed state?

A. NADPH production by the hexose monophosphate shunt is decreased

B. Acetoacetate is the major fuel for muscle

C. Glucose transport into adipose tissues is decreased

D. The major fuel used by the brain is glucose

84. All hormones acts through steroid receptor super family except:

A. Testosterone

B. Retinoids

C. Epinephrine

D. Vit. D

85. Which of the following statement about ribosomes is true?

A. They are composed of RNA,DNA and protein

B. They are composed of three subunits of unequal size

C. They are bound together so tightly they cannot dissociate under physiologic conditions

D. They are found both free in the cytoplasm and bound to membranes

86. Which one of the following structures may be classified as a hydrophobic amino acid at pH 7.0?

A. Arginine

B. Aspartic acid

C. Isoleucine                

D. Lysine  

87. The conversion of an optically pure isomer (enantiomer) into a mixture of equal amounts of both dextro and levo forms is called as:

(A) Polymerization.

(B) Stereo isomerization

(C) Racemization

(D) Fractionation.

88. Selenium is an essential component of:

(A) Glutathione synthetase

(B) Glutathione peroxidase

(C) Xanthine dehydrogenase

(D) Cytochrome oxidase

89. The reaction inhibited inthiamine deficiency is

(A) Pyruvate to acetyl CoA

(B) Citrate to alpha ketoglutarate

(C) Succinyl CoA to fumarate

(D) None

90. All of the following statements are correct about omega3 fatty acid except?

  1. Omega3 fatty acids replace omega6 (arachidonic acid) in cell membrane so they are cardio protective.
  2. An association between omega3 fatty acid and increase serum TG has been shown.
  3. Omega3 fatty acid may lower the production of thromboxane.
  4. Omega fatty acid are found in cold water fish such as salmon, tuna.

91. Which of the following is most suitable for separation of the most purified form of protein:

A. Liquid chromatography

B. Thin layer chromatography

C. Gel electrophoresis

D. Cellulose acetate electrophoresis

92. Fischer’s lock and key theory’ postulates that:

A. Active site in enzyme exists in proper conformation to the substrate molecule even in absence of substrate

B. Active site during binding to substrate under goes conformational changes to fit

C. There is absolute specificity in reaction between enzyme and substrate

D. Enzymes have catalytic power and accelerate reaction by reducing energy of activation

93. Which of the following serves as a storage molecule for high-energy phosphate groups in skeletal muscle?

A. The reaction has a positive DGo

B. The reaction has a negative DGo

C. Glucose-6 phosphate is unstable

D. There is no enzyme capable of catalyzing this reaction

94. Which of the following is most likely in an untreated child with PKU?

A. Elevated tyrosine

B. Cabbage like disorder

C. Decreased skin pigmentation

D. Normal phenylalanine hydroxylase levels

95. Which of the following is NOT a component of inter photoreceptor matrix?

A. Matrix metalloproteinase



D. Mimecan

96. Splicing is associated with:

A. mRNA          B. Sn RNA

C. r RNA           D. t RNA

97. Following SDS-PAGE electrophoresis, protein with is found to be 100 KD. After Rx with mercaptoethanol, it shows 2 bands of 20 KD and 30 KD widely separated. True statement:

A. Protein has undergone hydrolysis of S-S linkage

B. It’s a dimer of 2 subunits of 20 and 30 KD

C. It’s a tetramer of 2 20 KD and 2 30 KD

D. Protein breakdown due to non-covalent linkage

98. Serine proteases contain all of these amino acid  as their catalytic triad except:

A. Serine           B. Histidine

C. Alanine         D. Aspartate

99. True about isoenzymes is :

A. Same km value

B. Act on different substrate

C. Consist of multimeric complex

D. Same electrophoretic mobility

100. All are substrates required for PCR except

A. T AQ Polymerase

B. d NTP

C. Primer

D. Radiolabelled DNA probe

1.    A

2.    B

3.    C

4.    B

5.    C

6.    A

7.    B

8.    C

9.    A

10.    D

11.    B

12.    A

13.    C

14.    D

15.    A

16.    C

17.    D

18.    A

19.    D

20.    B

21.    B

22.    B

23.    D

24.    B

25.    A

26.    A

27.    B

28.    A

29.    B

30.    C

31.    C

32.    D

33.    D

34.    D

35.    B

36.    A

37.    A

38.    D

39.    C

40.    C

41.    D

42.    D

43.    C

44.    B

45.    C

46.   C

47.    A

48.    C

49.    A

50.    B

51.    D

52.    B

53.    A

54.    A

55.    A

56.    B

57.    C

58.    C

59.    B

60.    C

61.    D

62.    B

63.    B

64.    B

65.    C

66.    A

67.    B

68.    C

69.    D

70.    B

71.    D

72.    B

73.    C

74.    A

75.    B

76.    C

77.    A

78.    D

79.    D

80.    C

81.    C

82.    A

83.    D

84.    C

85.    D

86.    C

87.    C

88.    B

89.    A

90.    B

91.    D

92.    A

93.    B

94.    C

95.    D

96.    B

97.    A

98.    C

99.    C

100.    D


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