Biochemistry

Biochemistry – Solved University MCQ’s

BIOCHEMISTRY (A and B 2023/02 Mains)

1. An 8 year old child experiences episodes of hypoglycaemia,after eating fruits.Biochemical testing showed low activity of aldolase B in his liver cells.What is your most probable diagnosis?
a.Essential fructosuria b.Hereditary fructose intolerance c.Galactosaemia d.Type 1 diabetes mellitus
Answer:b
Hereditary fructose intolerance is an autosomal recessive disease characterized by absence of enzyme aldolase B. Aldolase B is an essential enzyme responsible for breakdown of fructose-1-phosphate into glyceraldehydes and dihydroxyacetone phosphate.

2.Major complication of the above condition is
a.Liver damage b.Renal failure c Retinopathy d. Cataract
Answer: a
Fructose 1 phosphate inhibits glycogen phosphorylase.As a result glycogen accumulates in liver causing karyorrhexis and karyolysis resulting in death of hepatocytes.

3. A 3 month old female infant suffers from bouts of vomiting and failure to gain weight.Plasma concentration of glutamine and ammonia were markedly elevated,but low concentration of citrulline was reported.The infant suffers from:
a.Parkinson’s disease b. Acquired hyperammonaemia c.Maple syrup urine disease d.Hereditary hyperammonaemia
Answer:d

4.The enzyme deficient in this infant is
a.Glutamate dehydrogenase b.Ornithine transcarbamoylase c.Glutamine synthetase d.Glutaminase
Answer:b

5. A 14 year old child with type 1 diabetes suffers burns during festival. His blood glucose should be carefully monitored because his daily insulin dose is likely to
a.Increase b.Decrease c.No change d.May increase or decrease depending upon body weight.
Answer: a

6. Reason for change in insulin dose in above patient is
a.Insulin is not only a metabolic hormone,it also plays role in blood clotting.
b.Stress induces insulin release from the pancreas.
c.Stress hormones antagonize insulin.
d.Psychological stress causes hypoglycaemia.
Answer:c

7.A full term infant born to normal and healthy parents was observed to have blue eyes and almost hair.Later he was found to be highly sensitive to damage from bright light.Name the clinical condition
a.Night blindness b.Albinism c.Cystinosis d.Cystinuria
Answer: b

8.The defective enzyme in the above condition is
a.Tyrosine hydroxylase bTyrosine transaminase c.Tyrosinase d.Phenylalanine hydroxylase
Answer: c
Tyrosinase catalyzes the rate limiting first step in melanin production.

9. Which of the following molecules is amphoteric
a.Phospholipids b.Triacylglycerols c,Cholesterol esters d.Alanine
Answer:d
Amino acids behave as acids in an alkaline medium and bases in an acidic medium.So, amino acids are amphoteric.

10.Given below are some hormonal disorders and their causes. Identify the mismatch
a,Myxodema Decreased secretion of thyroid hormones
b.Acromegaly Increased secretion of growth hormones
c.Cushing syndrome Decreased secretion of cortisol
d.Diabetes insipidus Decreased secretion of antidiuretic hormones
Answer: c
In Cushings syndrome steroid excess is there.

11.Given below are hormonal mechanisms for metabolic regulation.Identify the incorrect statement.
a.Glucocorticoids are released in chronic stress.
b.Insulin is a satiety hormone
c.Catecholamines mediate the flight or fight response
d.Parathormone is involved in regulating glucose homeostasis
Answer:d

12.Blood reports of some persons are given below. Identify the report suggestive of diabetes mellitus
a.Fasting plasma glucose 12 mg/dl b.Random plasma glucose 180 mg/dl
c.HbA1c 6.8% d.Prothrombin time 11 seconds
Answer:c. HbA1c normally should be below 5.7%.A level of 6.5 or above is suggestive of diabetes.

13.Which of the following compound(s) is NOT derived from cholesterol?
a.Vitamin D b.Cortisol c.Bile acids d.Riboflavin
Answer: d
Riboflavin is vitamin B2

14.Risk of myocardial infarction is greatly enhanced in the following disorders
a.Familial hyper cholesterolaemia b.Tangier disease c.Classical galactosaemia d.Maple syrup urine disease
Answer:b
Tangiers disease is characterized by significantly reduced levels of HDL in blood.HDL transports cholesterol and certain fats called phospholipids from body tissues to liver,where they are removed from blood.

15.Identify the laboratory report of the patient having obstructive jaundice
a.Urinary excretion of urobilinogen raised,serum alkaline phosphatase decreased
b. Urinary excretion of urobilinogen decreased,serum alkaline phosphatase increased
c. Urinary excretion of urobilinogen raised,serum alanine transaminase decreased
d. Urinary excretion of urobilinogen normal,serum aspartate transaminase decreased.
Answer:b

16.Given below are blood reports of some patients admitted in hospital emergency.Identify the one having maximum risk of myocardial infarction
a.Total cholesterol=150,HDL=25 b. Total cholesterol=155,HDL=30 c. Total cholesterol=160,HDL=35 d. Total cholesterol=165,HDL=40
Answer:a
Decrease in HDL is high risk of coronary artery disease.

17.Given below are some enzymes used for clinical diagnosis. Identify the mismatch
a.Gamma glutamyl transpeptidase Hepatitis,cirrhosis
b.Alkaline phosphatase Bone disease
c. Acid phosphatase Bone tumours
d.Aspartate transaminase Liver diseases
Answer:c
Question is not clear as all answers to some extent are true. Still c seems to be the best answer.

18.The following enzymes are elevated in serum of patient who has suffered a heart attack
a.Glutamate decarboxylase and glutamate dehydrogenase
b.Lactate dehydrogenase creatine kinase
c.Pyruvate dehydrogenase and glutaminase
d.Fructokinase and aldolase
Answer:b
Troponin and creatinine phosphokinase(CPK) levels rise after a heart attack.

19.A 46 year old alcoholic male was admitted in hospital emergency after he suffered from abdominal pain and blurring of vision.Six hours ago he had consumed a large quantity of a liquid thinking it was an alcoholic drink.Evidently he had mistakenly consumed a liquid thinking of it as the real stuff.He was treated with alcohol drip and he showed marked improvement.The patient suffered from
a.Methanol poisoning b.Cyanide poisoning c.Carbon monoxide poisoning d.Pentacholophenol poisoning
Answer:a
Fomepizole or ethanol serves as alcohol dehydrogenase inhibitors to stop the conversion of methanol to its toxic metabolite,formate.

20.All the following are exclusive duties of doctor’s in general EXCEPT
a.Displaying of registration number b.Manitaining medical records c.Exposure of unethical medical conduct d.Taking consent from the patient
Answer:c

21.The mutation that causes xerderma pigmentosum affects
a.The primase gene b.Nucleotide excision repair c.Mismatch repair components d.Synthesis of DNA across the damaged region
Answer:b
Here mutation occurs in protein responsible for excision of defective DNA synthesis.XPA to XPG are proteins responsible for this repair.Mutation causes XP disease making person prone to skin cancer.

22.Monoclonal antibodies are synthesized using
a.DNA finger printing b.Immunoelectrophoresis c.Hybridoma technology d.Fluorescence in situ hybridization
Answer:c
In this process antibody producing B lymphocytes are isolated from mice after immunizing the mice with specific antigen.These lymphocytes are then fused with immortal myeloma cell lines to form hybrid cells called hybridoma cell lines.

23.Mitochondrial DNA is inherited from
a.Mother only b.Father only c.Both of them d.Either father or mother
Answer:a

24.Acute intermittent porphyria is
a.Characterized by photodermatitis b.An autosomal dominant trait c.More common in men than women d.Hemolytic anaemia is associated
Answer:b

25.Compared to pH of blood urine normal pH is
A,Acidic b.Alkaline c.Neutral d.The same
Answer:a
pH of urine is 6.8

26.Conjugated hyperbilirubinemia with raised alkaline phosphatase levels are characteristic of:
a.Obstructive jaundice b.Hemolytic jaundice c.Viral hepatitis d.Physiological jaundice
Answer:a

27.In most of the cases hyperkalaemia results on account of
a.Liver failure b.Pancreatic failure c.Renal failure d.Tumors in bone
Answer:c
In DCT sodium is reabsorbed and potassium is excreted.If potassium not excreted due to renal failure hyperkalaemia occurs.

28.Which of the following groups of proteins assist in the folding of other proteins?
a.Proteases b.Proteosomes c.Templates d.Chaperones
Answer:d

29.Marasmus occurs from deficient intake of
a.Essential amino acids b.Essential fatty acids c.Calories d.Zinc
Answer:c

30.One of the following is the major component of extracellular matrix
a.Proteins b.Phospholipids c.Cholesterol d.Disaccharides
Answer:a

31.A 44 year old female with flushing non-healing ulcer ,diarrhea and bronchospasm with increased 5 HIAA levels
a.Glucagonoma b.Carcinoid c.Gastrinoma d.Insulinoma
Answer:b

32.A patient with increased hypoxanthine and xanthine in blood with hypouricemia. Which enzyme is deficient?
a.HGPR Tase b.Xanthine oxidase c.Adenosine deaminase d.APR Tase
Answer:b

33.Specific dynamic action(SDA) is greatest of
a.Protein b.Carbohydrates c.Fat d.Vitamin
Answer:a
Maximum energy is required to break proteins

34.A female child presented with growth retardation,anaemia,lethargy and her urine showed elevated levels of orotic acid.Treatment given should be
A,Uridine b.Thymine c.Cytosine d.Adenosine
Answer: a

35.In a man undergoing surgery, it was necessary to aspirate the contents of the upper gastrointestinal tract. After surgery the following values were observed from an arterial blood sample.pH 7.55Pco252mmHg and HCO340 mmol/LWhat is the underlying disorder?
a.Metabolic acidosis b.Metabolic alkalosis c.Respiratory acidosis d.Respiratory alkalosis
Answer:b
pH normally is 7.35-7.45. pH greater than 7.45, HCO3 greater than 24 mEq/l,PaCO2 greater than 45 indicate metabolic alkalosis

36.Clinical features of hyperthyroidism include
a.Goiter,heat intolerance,weight loss and tachycardia
b.Goiter,tremor,tachycardia and cold intolerance
c.Exophthalmos,goiter,tachycardia and loss of appetite
d.Exophthalmos,goiter,tremors and obesity.
Answer:a

37.The repeat sequence of nucleotides in telomers
a.TTGGGA b.TTAGGG c.GGGATT d.TTGAGG
Answer:b
Telomeres consist of six base repeating sequence TTAGGG

38.Which substance is not normally present in urine?
a.Creatinine b.Glucose c.Uric acid d.Urobilinogen
Answer:b

39.Standard urea clearance is calculated when output is
a.Less than 2ml/min b. More than 2ml/min c.2-4 ml/min d.More than 4 ml/min
Answer:a

40. An oncogene is
a.Usually a cell cycle inhibitor b.A mutated version of a normal viral gene c.Activated by cancer d.Active in normal human cells.
Answer:b

Biochemistry – A & B(2023/06 Supplementary)

41. A 45 year old man was admitted to hospital suffering from general fatigue, headache and stiff shoulder. He was diagnosed as hypertensive after his blood pressure was found to be 170/96 mm/Hg. Inhibitor of the following enzyme will help control the elevated blood pressure.

a. Renin
b. Beta-hydroxbutyrate dehydrogenase
c. Lipase
b. Angiotensin converting enzyme (ACE)

Answer:d

42. A 45 year old farmer was spraying an insecticide in fields. Suddenly he developed eye pain, headache and tightness in chest. He was taken to hospital where diagnosis of fluorophosphates (FP) poisoning was made. Biochemical basis of toxicity of FP is:

a. Irreversible inhibitor of an enzyme
b. Competitive inhibitor of acetylcholinesterase
c. Non-competitive inhibitor of acetylcholinesterase
d. Interference in electron transport chain

Answer:c

43. A 15 year old boy, who is having type-1 diabetes was brought to hospital in an unconscious state. He was on insulin therapy. A characteristic offensive smell was noticed in his breath. Blood glucose was elevated (428 mg/dl)

What is your most probable diagnosis

a. Respiratory acidosis
b. Lactic acidosis
C. Metabolic alkalosis
d. Diabetic ketoacidosis.

Answer:d

44. The offensive smell in breath is due to

a. Acetone
b. Acetoacetate
C. Beta-hydroxy butyrate
d.Lactate

Answer:a

45.A 26 year old man experienced severe pain in his right side and back. Subsequent investigations indicated a kidney stone. Increased urinary excretion of cystine, arginine and lysine in the urine was reported.

What is your most probable diagnosis
a. Cystinosis
b. Cystinuria
c. Homocysteinaemia
d. Phenylketonuria

Answer:b
46. Cause of the above disorder is
a. Transport defect
b. Enzymatic defect
c. Hormonal defect
d. Immuno-compromised state

Answer:b

47. True statement related to the above amino acid is

a. Cystine is an essential amino acid
b. Arginine is a semi-essential amino acid
c. Lysine is a non-essential amino acid
d. All three amino acids are glucogenic

Answer:d

48.A 14 year old boy with type 1 diabetes lost consciousness on racing track, while he was playing with his friends. He had received his normal insulin injection in the morning but continued playing forgetting his breakfast and lunch. He was given glucagon injection from the emergency kit his mother carried and recovered within minutes

The boy lost consciousness due to

a. Hyperglycaemia
b. Ketone bodies
c. Hyperlipidaemia
d. Hypoglycaemia

Answer:d

49. The tissue/organ which is most severely affected in the above condition is

a. Skeletal system
b. Haemopoietic system
c. Nervous system.
d. Vascular system

Answer:c

50. The following compound forms a link between Kreb cycle and Urea cycle
a. Fumarate
b. Succinate
c. Oxaloacetate
d. Malate

Answer:b

51. Rate and direction of glucose and glycogen metabolism in liver is controlled by
a. Estradiol
b. Glucagon
C. Aldosterone
d. Estrone

Answer:b

52. Near complete absence of the high density lipoproteins leads to the following disease:

a. Tangier disease
b. Fabry disease
c. Familial hypercholesterolaemi
d. Familial combined hyerlipidaemia

Answer:a

53. The term abetalipoproteinaemia refers to near complete absence of all of the following EXCEPT.
a. LDL
b. VLDL
c. Chylomicrons
d. HDL

Answer:d

54. GluTs promote entry of glucose into cells along a concentration gradient. This is an example of
a. Simple diffusion
b. Faciliated diffusion
c. Primary active transport
d. Secondary active transport
Answer:b

55. Hypoglycaemia compromises brain functions and is fatal when severe (blood glucose below 2.5 mmol/Liter). Severe hypoglycaemia may occur in:
a. Insulinoma
b. Fasting
c. Cigarette smoking
d. Cushing syndrome

Answer:a

56. When a person gets up in the morning 12 hours after dinner, the main source of his blood glucose is

a. Liver glycogenolysis
b. Gluconeogenesis
c. Muscle glycogen
d. Dietary glucose

Answer:a

57. Brain is an avid eater of glucose. During prolonged fasting its energy needs are covered from
a. Oxidation of muscle glycogen
b. Hepatic glycogenolysis
c. Anaerobic glycolysis
d. Oxidation of ketone bodies

Answer:a

58. All of the following are essential amino acids EXCEPT
a. Lysine
b. Leucine
c. Glycine
d. Phenylalanine

Answer:c

59. Competitive inhibitors bind with active site of an enzyme and cause
a. Increase in Vmax
b. Increase in Km.
c. Decrease in Km
d. Decrease in Vmax

Answer:b

60. All of the following are correct statements related to doctor patient communication EXCEPT:

a. One of the goals of effective doctor patient communication is facilitating exchange of information

b. Lesser doctor patient ratio is one of the reasons for bad doctor patient communication

c. Use of medical jargons is allowed while breaking bad news to the patient or patient’s family
d. Building rapport is one of the tools to improve doctor patient communication.
Answer:c

61. A 3 year old boy has a tendency to bite himself often to point of bleeding. The boy’s fingers show scarring and several scabs. His lips are swollen and bruised. He also has poor coordination, weak muscle tone and significantly delayed speech. The urine is orange in colour. Which of the following is the most likely diagnosis?

a. Tay-Sachs disease
b. Phenylketonuria
c. Lesch-Nyhan syndrome.
d Cerebral palsy

Answer:b

62. A 10 year old body develops severe diarrhea while traveling to India. The laboratory investigation revealed the following results:

Arterial blood pH = 7.25
Partial Pressure of carbon dioxide = 26 mmHg
Bicarbonate = 11 mEq/L with normal anion gap

What is the most probable diagnosis?

a. Metabolic acidosis
b. Metabolic alkalosis
c. Respiratory acidosis
d. Respiratory alkalosis

Answer:a
(Pa CO2>40 with a ph<7.4 indicates respiratory acidosis while Pa CO2<40 and Ph>7.4 indicates respiratory alkalosis)
Metabolic acidosis Pa CO2<40; distinguishing lab value is decreased bicarbonate(normal range is 21-28 mEq/L.The normal anion gap is 12

Metabolic alkalosis Ph>7.45;serum bicarbonate is elevated to >26 mole equilibrium/litre.Partial pressure of CO2 reduces to combat elevated bicarbonate)

63. A 10 year old boy complained of abdominal pain and was admitted in a hospital. He was weak and tried and had a history of seizures. The examination revealed an enlarged liver, Kayser- Fleishner ring in the cornea and low serum ceruloplasmin level. What is the most probable diagnosis?
a. Wilson’s disease.
b. Keshan’s disease
c. Tetany
d. Hartnup’s disease

Answer:a

64. Lead poisoning lead to increase in the accumulation and urinary excretion of coproporphyrin III and ALA in the urine. Which of the following enzymes are infibited by lead metal?
a. ALA synthase and protoporphyrin oxidase
b. ALA synthase and coproporphyrin oxidase
c. ALA dehydratase and protoporphyrin oxidase
d. ALA dehydratase and ferrochelatase

Answer:c

65. Which of incorrect in xeroderma pigmentosum
a. It is an autosomal recessive conditions
b. Defect is in the repair mechanism of DNA
c. Sensitivity to UV light is the major manifestation
d. Cells are unable to synthesize vitamin-D even in the presence of sunlight

Answer:d

66. The enzyme used in the complementary DNA synthesis is
a. Restriction endonuclease
b. Taq DNA polymerase
C. Reverse trascriptase
d. Ligase

Answer:b

67. Lac operon is active when
a. Only glucose is available in medium
b. Only lactose is available
c. CAMP is low
d. Both lactose and glucose are available

Answer:a

68. A 3 year old girl was brought to the pediatric OPD with complaints of mild generalized swelling all over the body, loss of appetite, low grade fever and distended abdomen. She belonged to low socioeconomic group. Weight and height were lower as compared for her age group. What is the most probable diagnosis?
a. Kwashiorkar
b. Marasmus
c. Irritable bowel syndrome
d. Ulcerative colitis

Answer:a

69. Vitamin K activates the following clotting factor except:
a. Prothrombin
b. Factor VII
c. Factor V
d. Factor IX.

Answer:a

70. Marfan’s syndrome is caused by the following defective protein:
a. Fibrinogen
b. Fibronectin
c. Fibrillin
d. Collagen

Answer:c

71. An increase in serum unconjugated bilirubin occurs in
a. Hemolytic jaundice
b. Obstructive jaundice
c. Defects in intestinal absorption
d. Glomerulonephritis

Answer:a

72. The urine of the patient with obstructive jaundice will give a positive test for:
a. Fouchet’s test
b. Benzidine test
c. Sodium nitroprusside test
d. Precipitation test

Answer:d

73. What is a nucleosome?
a. Synonym of nucleolus
b. DNA-RNA complex present in nucleus
C. mRNA attached with snRNA
d. DNA wrapped around histones

Answer:a

74. In primary hypothyroidism, the lab findings are
a. Decreased TSH
b. Increased TSH.
C. Increased T3
d. Increased T4

Answer:b

75. A technician notices that an undiscarded urine has become black on long standing. This may be due to the presence of which substance in the urine?
a. Homogentisic acid
b. Phenylalanine
c. Homocystine
d. Tyrosine

Answer: a

76. A CSF glucose of 15mg/dL, WBC count of 5000, 90% noutrophilis and protein of 81 mg/dl suggests
a. Fungal meningitis
b. Viral meningitis
C. Tubercular meningitis
d. Bacterial meningitis

Answer:a

77.A 70 year old male was brought to the emergency with great difficulty in passing urine. There had been significant loss in weight in last months. Investigations were sent for the probable diagnosis of carcinoma prostate. Which of the following marker will support the diagnosis?
a. Alkaline phosphatase
b. Tissue specific antigen
c. Prostate specific antigen.
d. CA125

Answer:c

78. The following is NOT a proto oncogene:
a. c-myc
b. Tyrosine kinase gene
c. p53.
d. cycline

Answer:c

79. A 50 year old man developed an excruciating pain in the first toe with swelling and redness. On investigation, serum uric acid was 12 mg/dl. Synovial fluid examination revealed needle shaped birefringent crystals. What is the most probable diagnosis?
a. Gout
b. Scurvy
c. Osteomalacia
d. Phenylketonuria

Answer:a

80. The inhibitor of iron absorption is
a. Phytate.
b. Lysine
C. Vitamin C
d. Gastric HCL

Answer:a

81. Which one of the following reactions is unique to Gluconeogenesis?
a. Lactate Pyruvate
b. Phosphoenolpyruvate → Pyruvate
c. Oxaloacetate Phosphoenolpyruvate
d.Glucose 6-Phosphate Fructose 6-Phosphate
Answer:c

82. The Lipoprotein with the fastest electrophoretic mobility and the lowest TG content is:
a. VLDL
b. IDL
c. LDL
D. HDL
Answer:d
83. A competitive inhibitor of an enzyme :
A. Increases Km but does not affect Vmax
B. Decrease Km but does not affect Vmax
C. Increase Vmax but does not affect Km
D. Decreases both Km and Vmax
Answer:a
84. PGE2 has which of the following action on kidney when infused intravenously
A. Increases re-absorption of water vane
B. Increases excretion of sodium
C. Decreases the Rennin secretion from JG Cells
D. Decreases the GFR
Answer: a
85. Erythrocyte glucose transporter is an example of?
A. Facilitated diffusion
b. Ion driven active transport
c. Active transport
d. Simple diffusion
Answer:a
86. The mechanism of action of Oligomycin, an inhibitor of ETC, is:
a. Blocking Electron Transport
b.Inhibition of ATP Synthase
C. Inhibition of ADP-ATP Translocation
d. Uncoupling of Electron transport and Oxidative Phosphorylation
Answer: b
87. An enzyme in Human Saliva is able to hydrolyse the 0,-1,4 glucosidic bonds in the molecule of starch. Which is this enzyme?
a. α-amylase
b. B-amylase
c. B-galactosidase
d. Diastase
Answer: a
88. Methotrexate is a pharmacological inhibitor of which of the following enzyme:
a. Xanthine Oxidase
b. Dihydrofolate Reductase
c. Thymidylate Synthase
d. Ribonucleotide Reductase
Answer:b

89. The breakdown of one molecule of C16 saturated fatty acid by B-oxidation leads to the formation of-
a. 8 FADH2, 8 NADH and 8 Acetyl-CoA molecules.
b. 7 FADH2, 7 NADH and 7 Acetyl-CoA molecules
c. 8 FADH2, 8 NADH and 7 Acetyl-CoA molecules
d. 7 FADH2, 7 NADH and 8 Acetyl-CoA molecules.
Answer: d
90. The process of reconversion of lactate formed in muscles and RBC’s, back into Glucose inside the Liver is called:
a. Cahill Cycle
b. Cori’s Cycle
c. Pyruvate-Alanine Cycle
d. Dicken’s Horecker Cycle
Answer:b
91. A 32 year old body builder goes on a diet consisting of only egg whites to ensure only proteins for muscle growth. Which vitamin deficiency is he most likely to suffer from-
a. Niacin
b. Biotin
c. Pyridoxine
d. Thiamine
Answer:a
92. The marker enzyme for Lysosomes is-
a. Lactate Dehydrogenase
b. ATP synthase
c. Galactosyl Transferase
d. cathepsin
Answer:?? The marker enzyme for lysosomes is Acid Phosphatase.

93. A 42-year-old obese female presented to the emergency, complaints of worsening nausea, vomiting and abdominal pain-located in the mid epigastric area and right upper quadrant. Blood biochemistry revealed high amylase level. What is the probable diagnosis in this case-?
a. Viral Hepatitis
b. Renal Colic
c. Acute Pancreatitis
d. Acute Gastritis
Answer:c

94. A young student develops a hemolytic condition soon after taking Primaquin prophylaxis against malaria. The most likely cause of hemolysis is a less than normal level of-
a. Reduced form of glutathione
b. Glucose-6-phosphate dehydrogenase
c. Oxidised from of NAD
d. Ribose-5-phosphate
Answer:b
95. Which of the following condition decreases the oxidation of Acetyl CoA by the citric acid cycle-
a. A low ATP/ADP Ratio
b. A low NAD+/ NADH ratio
c. A high concentration of AMP
d. A low NADH concentration due to rapid oxidation to NAD+ through the respiratory chain
Answer:b
96. Deficiency of which of the following enzymes would impair the body’s ability to maintain blood glucose concentration during first 24 hours of a prolonged fact-
a. Phosphorylase
b. Debranching enzyme
c. Glycogen Synthase
d. PEP Carboxykinase
Answer:a
97. Which of the following is the most common type of hyperlipidaemia in diabetes mellitus?
a. Elevated Triglyceride with normal cholesterol
b. Normal Triglyceride with elevated cholesterol
c. Decreased Triglyceride with elevated cholesterol
d. Elevated Triglyceride and cholesterol
Answer: d
98. Which is the cofactor required for treatment of Methylmalonic acidemia?
a. Thiamine
b. Riboflavin
c. Vit B12
d. Biotin
Answer:c
99. Ferric Chloride test in urine is positive in which of the following condition-
a. Homocystinuria
b. Alkaptonuria
c. Tyrosinosis
d. Phenylketonuria
Answer:d
100. Microalbuminuria is defined as urinary albumin levels of-
a. 30-300 mg/24 hr
b. 100-150 mg/24 hr
c. 151-200 mg/24 hr
d. 301-600 mg/24 hr
Answer: a
101. Which of the following enzyme is deficient in maple syrup urine disease?
a. Branched chain amino acid aminotransferase
b. Branched chain amino acid dehydrogenase
c. Branched chain keto acid dehydrogenase
d. Branched chain keto acid oxidase
Answer: c
102. Which of the following phospholipid is associated with apoptosis?
a. Phosphophatidylcholine
b. Dipalmitoylphosphatidylcholine
c. Phosphatidylserine
d. Phosphatidylinositol 4,5-bisphosphate
Answer: c
103. Carnitine helps in
a. Transport of fatty acids from mitochondria to cytosol
b. Transport of fatty acids from cytosol to mitochondria
c. Transport of pyruvate in to mitochondria
d. Transport of Malate in Malate shuttle
Answer: b
104. The rate of ketone body production is mainly determined by the relative rate of which of the following key metabolic pathways?
a. Proteolysis
b. Glycogenolysis in muscle
c. Glycolysis
d. Lipolysis,
Answer: d
105. Which of the following is the allosteric activator of Acetyl-CoA carboxylase?
a. Malonyl-CoA
b. Acetyl-Co-A
c. Citrate
d. Biotin
Answer: c
106. Which of the following is the common precursor in the synthesis of all steroid hormones?
a. Pregnenolone
b. 17-OH pregnenolone
c. Isocaproaldehyde
d. Androstenedione
Answer: a
107. Lipoprotien with least electrophoretic mobility is
a. Chylomicrons
b. VLDL
c. LDL
d. LHDL
Answer: a
108. Which ofthe following fatty acid present in fish oil is known for its cardio protective action?
a. Arachidonic acid
b. Eicosapentaenoic acid
c. Linoleic acid
d. Palmitic acid
Answer:b
109. Inhibition of which of the following enzyme is responsible for the anticancer action of 5- fluorouracil?
a. Dihydrofolate reductase
b. Thymidylate kinase
c. Thymidylate reductase
d. Thymidylate synthase
Answer: d
110. Which of the following glucose transporters are located in the brain?
a. GLUT1 and GLUT 2
b. GLUT1 and GLUT 3
c. GLUT 2 and GLUT 3
d. GLUT 2 and GLUT4
Answer: b
111. Which one of the following bonds links two nucleotides in a nucleic acid?
a. 3’3′ phosphodiester bond
b. 3′->5′ phosphodiester bond
C. 5′ 5′ phosphodiester bond
d. 5′->5′ phosphotriester bond
Answer: b
112. DNA glycosylase is involved in:
a. Mismatch repair
b. Base excision repair
c. Nucleotide excision repair
d. direct repair
Answer:b
113. The technique for accurate quantification of gene expression is:
a. Northern Blot
b. PCR
c. Real Time Reverse Transcriptase PCR
d. Reverse Transcriptase PCR
Answer: a
14. Poly A tail is translated into:
a. Polylysine
b. Polyglutamate
c. Polyproline
d. NONE
Answer: d
115. The initiator AUG in Prokaryotes codes for
a. Methionine
b. N-Formyl methionine
c. Phenyl alanine
d. Tyrosine
Answer: a
116. Which one of the following is an example of post translational modification?
a. Cycloheximide
b. Puromycin
c. Paromomycin
d. Erythromycin
Answer: c

117. Which of the following gene is constitutively expressed in E.coli?
a. Lac A
b. Lac I
c. Lac Y
d. Lac Z
Answer: b
118. All of the following vitamins are antioxidants, EXCEPT:
a. Vitamin A
b. Vitamin C
c. Vitamin d
d. Vitamin e
Answer:d
119. To diagnose which of the following deficiency schilling test is used?
a. Vitamin B12
b. Folate
c. Iron
d. Vitamin C
Answer:a
120. All the following proteins are involved in the
a. Metabolism of iron, EXCEPT
b. Ceruloplasmin
c. Ferritin
d. Hepcidin
Answer:b

Biochemistry (Paper A and B Feb 2023/02 Mains)

Q.2 A mother of new born baby came to OPD and described that baby is having irritability,feeding problem and abnormal movements.Biochemical analysis showed metabolic acidosis and urine analysis showed presence of ketone bodies and burn sugar smell(2+2+5+3)

a.What is the most probable diagnosis?
b.Which amino acids are likely to be increaded in blood and urine?
c.Explain defective pathway?
d.What is biochemical basis for symptoms?

Q3.Write short notes on 5×4
a.Effect of temperature on enzymes activity
b.Heteropolysaccharides
c.21st amino acid
d.Essential fatty acids

Q4.Explain why: 3×5
a.Ethanol is used in methanol poisoning
b.Thyroxine hormone maintains BMR
c.Galactosemic infants present with premature cataract
d.Fatty acid oxidation defect leads to non ketolic hypoglycemia
e.Carcinoid syndrome leads to pellagra

Q5.Write short notes on
a.Regulation of glycogen metabolism 6×3
b.Enzyme inhibition with special emphasis on suicidal enzyme inhibition
c.Discuss VLDL metabolism

Q6 Write short notes on5x3
a.Metabolic alteration in starvation
b.Biochemical function of vitamin C
c.Boundaries of doctor patient relationship

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Q2.An elderly couple was found unconscious early morning by the help.It was noticed that angithi was burning and all the doors and windows were shut. (3+4+3+2)
a.What is the most probable diagnosis?
b.What is the biochemical basis behind loss of consciousness?
c.How is such a condition managed?
d.Explain the cause,manifestation and management of any other condition which can lead to loss of consciousness in an elderly person?

Q3Write short notes on 5×4
a.Alternative splicing
b.Probes
c.Polymersase chain reaction
d.Okazakin fragments

Q4 Explain why 3×5
a.CD4/CD8 ratio is reduced in AIDS
b.Blood group is done before transfusion
c.Diet rich in folic acid is recommended in first trimester of pregnancy
d.Vaccines are given to infants
e.p53 is called a tumor suppressor gene

Q5 Write short notes on 6×3
a.Renal function tests
b.Extracellular matrix
c.Kwashiorkor and Marasmus

Q6.Write short notes on 5×3
a.Regulated expression of a gene
b.Humoral immunity
c.Aspect of non verbal communication

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Biochemistry (Paper A and B 2023/06 Supplementary)

Q.2 A new born baby developed jaundice on 3rd day after the birth. Blood test revealed unconjugated hyperbilirubinemia.(3+4+3+2)

a. What is the diagnosis?
b. What are the probable causes of developing this condition?
c. How is such a case managed?
d. Give two causes of conjugated hyperbilirubinemia.

Q.3. Write short notes on(5×4)
a. Glutathione
b. Glycosides
C. Micelles
d. Glycated hemoglobin

Q.4. Explain why (3×5)
a. Trans fatty acids are harmful.
b. Curd is advised in patients with lactose intolerance
C. Phenylketonuric infants are fair
d. Exercise intolerance is observed in McArdle disease.
e. Dietary fibers are beneficial for health

Q.5. Write short notes on (6×3)
a. Role of enzymes in diagnostic
b. Biochemical basis of toxicity of hyperammonemia
C. Biochemical role of vitamin A

Q.6. Write short notes(5×3)
a. Discuss the types of doctor-patient relationship.
b. Discuss the causes and consequences of alcoholics.
C. Discuss the regulation of ketone body metabolism.

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Q.2. An obese (BMI 32 kg/m2) 45 year old male presented to the emergency with acute chest pain radiating to left arm. His ECG showed changes typical of an acute myocardial infarction.
a. Name the biomarkers having specificity for myocardial infarction.(2+5+2+3)
b. Draw a graph to show the time of onset of cardiac biomarker elevations in acute myocardial infarction.
C. How is BMI calculated?
d. What is atherosclerosis?

Q.3. Write short notes on(5×4)
a. Messenger RNA
b. Restriction enzymes
c. Initiation of protein synthesis
d. Role of non-verbal gestures in doctor-patient communication

Q.4. Explain why (3×5)
a. Creatinine is a better assessor of kidney function than urea.
b. Hyper ammonemia occurs in urea cycle defects.
C. Antigen presenting cells have a major role in cellular immunity.
d. Pedigree chart is important tool in prenatal diagnosis of thallasemias.
e. Monoclonal antibodies are required in laboratory for diagnosis of some disease.

Q.5. Write short notes on(6×3)
a. Tumor markers
b. Vitamin A
c. Thyroid function tests

Q.6. Write short notes(5×3)
a. Post transcriptional modifications
b. Nutritional anaemias
c. Fatty acid synthesis

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Biochemistry 2023/11(Mains A and B)

Q.2 A 3 year old boy is brought to the hospital OPD with complaints of delayed developments and inability to speak or walk properly.On examination the boy was fpound to be mentally retarded with characteristic tremors.On examination the boy had areas of hypopigmentation on skin and hair.His urine was found to have a mousy odour and gave a positive ferric chloride test.(2+2+3+3+2)
a.What is the most probable diagnosis?
b.What is the enzyme deficiency in this disorder?
c.What is the biochemical basis of mental retardation in this case?
d. What is the biochemical basis of hypopigmented skin and hair in this case?
e.What are the investigations and treatment suggested for this disorder?

Q.3.Write short notes on:-5×4

a. Compare and contrast primary and secondary structure of proteins with examples and diagrams.
b. Define ketone bodies.Explain briefly their synthesis and degradation in our body.
c. Explain primary and secondary active transport mechanism with suitable examples.
d. Classify enzymes with suitable examples.

Q.4 Explain why: -3×5

a. HMP shunt is important for our body
b. HbA1C test is used for monitoring of diabetes mellitis
c. Hexokinase is preferred over Glukokinase for blood glucose estimation.
d. Fruity smell from mouth is seen in diabetic ketoacidosis
e. HDL is called good cholesterol.

Q.5. Short notes on:6×3

a. Enumerate the diagnostic markers of Myocardial Infarction(MI).Explain with diagram the pattern of rise of these markers following an acute MI.
b. Define oxidative phosphorylation.Discuss the inhibitors of electron transport chain(ETC)
c. Explain briefly the role of hormones in regulation of blood glucose in our body.

Q.6. Short notes:-5×3

a. Biochemical function of vitamin D
b. Eicosanoids and their clinical applications
c. Role and duties of a patient.
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2. A 45 year old woman presented to the OPD with the complaints of palpitation,tremors in her hands,diarrhea and significant loss of weight.On examination she had tachycardia and fine tremors in the handswhen stretched out.ECG findings were consistent with sinus tachycardia .Her thyroid profile report is as follows:.(4+3+2+3)
Parameter Patient value Biological reference range
FT3 6.2pg/ml 1.2-4.4pg/ml
FT4 27microg/dl 5.0-12.0microg/dl
TSH 0.03 mIU/L 0.5-5mIU/L

a.Interpret the thyroid profile and suggest a provisional diagnosis.
b.Explain the biochemical basis of her presenting complaints.
c.i.Enumerate any two conditions which can lead to such a picture.
ii.Explain the biochemical basis of any one of them.

3. Write short notes on:-5×4

a. Antibody dependent cell mediated cytotoxicity
b. Structure of tRNA
c. Chemical carcinogenesis
d. Functions of glycosaminoglycans

4.Explain why:-3×5

a.Intake of rice and pulses together is beneficial
b. Uracil is present in RNA but not in DNA
c. Bleeding diathesis is common in obstructive jaundice
d. Anaemia is observed in chronic renal failure
e. Patients with extensive burns are prone to infections

5. Short notes on:-6×3

a. Renal function tests
b. Base excision repair
c. Compare and contrast apoptosis and necrosis

6. Short notes on:-5×3
a. Role of a Physician in the society
b. Vaccines
c. Southern blotting

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