[MANOR] Biochemistry - Practice Questions

Proverbs 16:3

B) binds simultaneously with substrate other than the active site

1. The inhibition in noncompetitive reaction ________.
   a) competes with the active site of the enzyme
   b) binds simultaneously with substrate other than the active site
   c) increases the rate of reaction
   d) both b and c

A) primary

2. The order and sequence of amino acid in a polypeptide determines what protein structure
   a) primary
   b) secondary
   c) tertiary
   d) quaternary

B) essential amino acids

3. Amino acids that cannot be synthesized in the organism are called __________.
   a) non essential amino acids
   b) essential amino acids
   c) standard amino acids
   d) alpha amino acids

A) aldosterone

4. Which hormones regulates the level of blood sodium?
   a) aldosterone
   b) sterol
   c) corticosteroid
   d) cortisone

A) B-carotene

5. It is a precursor of vit. A
   a) B-carotene
   b) retinol
   c) retinal
   d) opium

C) cholesterol

6. Which of the following is a precursor of vitamin D?
   a) prostaglandin
   b) linoleic acid
   c) cholesterol
   d) aldosterone

B) dehydrolase

7. Which of these class of enzymes introduces double-bond by the removal of hydrogen
   a) dehydrogenase
   b) dehydrolase
   c) decarboxylase
   d) lipase

A) zwitterions form

8. The ionic property of amino acid is exhibited by its
   a) zwitterions form
   b) NH2 group
   c) COO group
   d) positively charged groups

D) glycoproteins

9. All of the following are simple proteins except:
   a) glutelins
   b) globulins
   c) albumins
   d) glycoproteins

C) glyceraldehydes

10. The simplest monosaccharide is
    a) erythrose
    b) starch
    c) glyceraldehydes
    d) arabinose

C) breaking of H-bond

11. Denaturation of protein is a result of
    a) cleavage of the peptide bond
    b) formation of H-bond
    c) breaking of H-bond
    d) none of these

A) reversible

12. Competitive inhibition is a _______ reaction.
    a) reversible
    b) irreversible
    c) pH & temperature dependent
    d) none of these

A) hydroxymethyl furfural

13. In the Seliwanoff's test, the reaction of resorcinol and acid on the sugar forms___________.
    a) hydroxymethyl furfural
    b) pyranose
    c) hydrazine
    d) purine

A) competitive inhibition

14. It is the type of enzyme inhibition reaction whereby the inhibition competes with the substrate active site.
    a) competitive inhibition
    b) noncompetitive
    c) reversible inhibition
    d) incomplete inhibition

C) bile acids

📌The following are waxes

• Beeswax

• Sperm oil

• Lanolin

15. The following are waxes except:
    a) beeswax
    b) sperm oil
    c) bile acids
    d) lanolin

A) zymogens

16. The inactive form of enzymes are called ______.
    a) zymogens
    b) apoenzymes
    c) cofactor
    d) both B & C

D) both a and b

• Proline

• Hydroxyproline

17. Which of the following amino acids has no alpha amino group?
    a) proline
    b) hydroxyproline
    c) glycine
    d) both a and b

B) act as a catalyst

18. An enzyme is a substance which
    a) convert heat to energy
    b) act as a catalyst
    c) change chemically in reaction
    d) is not specific in reaction

B) rennin

19. Milk curdling enzyme present in gastric juice of infants:
    a) pepsin
    b) rennin
    c) trypsin
    d) maltase

A) polyhydroxyaldehydes / polyhydroxyketones

20. Carbohydrates are:
    a) polyhydroxyaldehydes / polyhydroxyketones
    b) polyhydroxy acids
    c) hemiacetals
    d) polymers of amino acids

C) hormone

21. Insulin is usually classified as:
    a) protein
    b) enzyme
    c) hormone
    d) carbohydrates

A) 60 to 90 mg in 100 ml blood

22. What amount of glucose is present in the human blood?
    a) 60 to 90 mg in 100 ml blood
    b) 5 to 6 g in 100 ml blood
    c) 2% of the total human body weight
    d) none of these

A) mitochondria

23. It is the organelle which serves as the site of the electron transport chain.
    a) mitochondria
    b) ribosome
    c) nucleus
    d) lysosome

C) glucose

24. The end product of the hydrolysis of glycogen is:
    a) galactose
    b) fructose
    c) glucose
    d) arabinose

C) presence of amylose portion

25. Iodine test is a reaction which may be used to identify carbohydrates. The reaction is due to
    a) presence of the free aldehyde group
    b) presence of alcohol group
    c) presence of amylose portion
    d) presence of glucose

B) reducing sugars

26. Benedict's reagent yield positive result to:
    a) monosaccharide only
    b) reducing sugars
    c) sucrose
    d) polysaccharides

B) shrink

27. Hypertonic solutions will cause the cell to:
    a) swell
    b) shrink
    c) burst
    d) undergo hemolysis

A) oxidation

28. Rancidity of fats maybe due to:
    a) oxidation
    b) hydrogenation
    c) saponification
    d) condensation

C) insulin

29. The deficiency of this hormone causes diabetes mellitus:
    a) progesterone
    b) testosterone
    c) insulin
    d) glucagon

A) pepsin

30. The active proteolytic enzyme in gastric juice is:
    a) pepsin
    b) trypsin
    c) maltase
    d) catalase

B) mitochondrion

31. The site of oxidation reaction in electron transport chain is in the
    a) nucleus
    b) mitochondrion
    c) ribosome
    d) golgi bodies

B) stomach

32. Protein digestion starts in the ______
    a) mouth
    b) stomach
    c) intestine
    d) pancreas

A) gluconeogenesis

33. The conversion of an amino acid to sugar is:
    a) gluconeogenesis
    b) glycolysis
    c) glycogenesis
    d) glycogenolysis

B) choline

34. Which of the following is not an amino acid?
    a) leucine
    b) choline
    c) valine
    d) glycine

C) enterokinase

35. When trypsinogen is converted into trypsin, the enzyme is called:
    a) pepsin
    b) zymogen
    c) enterokinase
    d) amylase

A) apoenzyme

36. The protein part of the enzyme molecule is the:
    a) apoenzyme
    b) coenzyme
    c) cofactor
    d) holoenzyme

C) 37°C

37. Optimum temperature for enzyme activity in the body:
    a) 40°C
    b) 60°C
    c) 37°C
    d) 10°C

B) glycogen

38. Glucose is stored in the liver, as:
    a) galactose
    b) glycogen
    c) lactose
    d) fructose

A) Lock and Key theory

39. The enzyme conformation adapts to the incoming substrate in
    a) Lock and Key theory
    b) glycogenesis
    c) competitive inhibition
    d) glycogenolysis

B) glycogenesis

40. The process of converting glucose into glycogen is called
    a) gluconeogenesis
    b) glycogenesis
    c) glycolysis
    d) glycogenolysis

A) guanine

📌Rationale: Guanine is a purine base (double-ring structure), not a pyrimidine.

• Cytosine — pyrimidine base

• Uracil — pyrimidine base

• Thymine — pyrimidine base

41. All are pyrimidine bases except:
    a) guanine
    b) cytosine
    c) uracil
    d) thymine

B) acetyl CoA

42. Glucose, amino acid and fatty acid enter the citric acid cycle by their conversion into:
    a) pyruvate
    b) acetyl CoA
    c) acetoacetyl CoA
    d) palmitic acid

A) insulin

43. A hormone which stimulates glycogenesis:
    a) insulin
    b) glucagon
    c) epinephrine
    d) vasopressin

A) antibiotic

44. These are chemicals that are extracted from organism such as bacteria and can inhibit growth or destroy other microorganisms:
    a) antibiotic
    b) enzyme
    c) hormone
    d) vitamins

C) pancreas

45. The gland or tissue that regulates the blood glucose level.
    a) parathyroid
    b) thyroid
    c) pancreas
    d) adrenal

D) vit. D

46. Which vitamin is formed in the body by exposure to ultraviolet irradiation or sunlight
    a) vit. A
    b) vit. B
    c) vit. C
    d) vit. D

C) both a & b

47. Excess vit. A & D is stored in the body, but excess vit. C & B is readily excreted. What property shows this?
    a) vit C & B are water soluble
    b) vit. A & D are fat soluble
    c) both a & b
    d) none of these

B) vit. B complex

48. The vitamin which is used in the prevention of degenerative changes in the central nervous system.
    a) vit. A
    b) vit. B complex
    c) vit. C
    d) vit. D

A) lock & key

49. It is a model which best explains the enzyme-substrate action
    a) lock & key
    b) molecular
    c) VSEPR
    d) Krebs

D) HCl

50. The activation of pepsinogen requires:
    a) pepsin
    b) NaOH
    c) enterokinase
    d) HCl

B) nucleus/mitochondria

51. DNA is primarily found in the
    a) cytosol
    b) nucleus/mitochondria
    c) cell wall
    d) endoplasmic reticulum

B) amylase

52. It is the enzyme which hydrolyzes starch to dextrin and maltose
    a) catalase
    b) amylase
    c) pepsin
    d) lactase

D) recombinant DNA

53. A synthetic DNA is called
    a) replicated DNA
    b) plasmid
    c) gene
    d) recombinant DNA

B) energy producing reaction

54. Hydrolysis of ATP is an
    a) energy requiring reaction
    b) energy producing reaction
    c) no energy is involved
    d) energy is absorbed

C) hydrophobic

55. Which of the following characteristic of lipid?
    a) zwitterions
    b) amphiphilic
    c) hydrophobic
    d) hydrophilic

A) hypoglycemia

56. It is a condition that results when sugar level is below normal
    a) hypoglycemia
    b) hyperglycemia
    c) ketonuria
    d) uremia

A) albumin

57. An example of globular protein
    a) albumin
    b) collagen
    c) fibrin
    d) silk

A) H-bond

58. Complementary base pairs in the DNA double helix are bonded by ________
    a) H-bond
    b) ester bond
    c) van der Waals
    d) dipole-dipole

C) uracil

59. Which nitrogen base is not found in DNA?
    a) thymine
    b) cytosine
    c) uracil
    d) guanine

C) a & b

• vitamins

• coenzyme

60. An organic cofactor in an enzyme
    a) vitamins
    b) coenzymes
    c) a & b
    d) none of these

B) aerobic stage

61. At what stage of glucose oxidation is most of the energy produced?
    a) glycolysis
    b) aerobic stage
    c) glycogenesis
    d) glycogenolysis

D) a and b

• purines

• pyrimidines

62. The best known building blocks of RNA and DNA are
    a) purines
    b) pyrimidines
    c) fatty acids
    d) a and b

C) DNA

63. It is responsible for the storage and transmission of genetic information.
    a) adenine
    b) RNA
    c) DNA
    d) nucleic acid

C) uremia

64. Build up of urea in the kidney is called
    a) ketonuria
    b) glycemia
    c) uremia
    d) all of these

A) transcription

65. The transfer of genetic information from DNA by the formation of mRNA
    a) transcription
    b) translation
    c) transamination
    d) replication

D) water

66. What is the end product of electron transport chain?
    a) oxygen
    b) hydrogen
    c) carbon dioxide
    d) water

B) catabolic

67. The energy producing reaction
    a) metabolic
    b) catabolic
    c) anabolic
    d) all of these

D) hormones

68. It is the molecule that directs the activity of the cells
    a) DNA
    b) RNA
    c) nucleoproteins
    d) hormones

C) deoxyribose

69. The sugar involved in DNA
    a) ribose
    b) pentose
    c) deoxyribose
    d) xylose

C) Krebs cycle

70. The common metabolic pathway
    a) glycolysis
    b) beta oxidation
    c) Krebs cycle
    d) glucogenesis

B) choline

71. Rosenheim's test is used to detect the presence of:
    a) ethanolamine
    b) choline
    c) cholesterol
    d) glycone moiety

C) Ninhydrin

72. Detects the presence of alpha amino acids:
    a) Biuret
    b) Molisch
    c) Ninhydrin
    d) Hopkins-Cole

B) lipogenesis

73. The process of producing fats from acetyl CoA is called
    a) glycolysis
    b) lipogenesis
    c) glycogenolysis
    d) glucogenesis

A) Grignard's

74. The following test reagents to detect the presence of amino acids, except:
    a) Grignard's
    b) Xanthoproteic
    c) Millon-Nasse
    d) Sakaguchi

A) acidosis

75. The condition that lowers the pH of the blood due to starvation is called _______
    a) acidosis
    b) alkalosis
    c) hyperglycemia
    d) glycosuria

B) bile acids

76. The substance responsible for the emulsion of fats is _______
    a) HCl
    b) bile acids
    c) pepsin
    d) trypsin

B) unsaturation

77. Hubl's solution is used to ascertain degree of:
    a) saturation
    b) unsaturation
    c) peroxidation
    d) acidity

B) propenal

78. IUPAC name of acrolein
    a) pentenal
    b) propenal
    c) hexanal
    d) acetone

B) black markings on filter paper

79. The positive indication for the presence of glycerol in acrolein test:
    a) yellow colored solution
    b) black markings on filter paper
    c) silver mirror formed in the test tube
    d) play of colors, from blue to shades of red

B) Biuret

📌NOTE: Cerebrosides are positive in:

• Molisch test

• Lassaigne’s test

80. Cerebrosides are positive in the following tests, except:
    a) Molisch
    b) Biuret
    c) Lassaigne's
    d) none of the above

C) unsaturated groups

81. Osmic test is used to detect the presence of _______ in lipids:
    a) metals
    b) prosthetic groups
    c) unsaturated groups
    d) glycerol

A) Liebermann-Burchard

82. The most sensitive chemical test to detect the presence of cholesterol:
    a) Liebermann-Burchard
    b) Salkowski reaction
    c) Formaldehyde-sulfuric acid
    d) Colorimetric spectrophotometry

D) choline

📌NOTE: Choline is a component used in phospholipid synthesis , not a phospholipid itself.

• plasmalogen — a phospholipid with a vinyl-ether linkage

• lecithin — phosphatidylcholine, a phospholipid

• cephalin — phosphatidylethanolamine, a phospholipid

83. The following are phospholipids, except:
    a) plasmalogen
    b) lecithin
    c) cephalin
    d) choline

C) three different fatty acids esterified with glycerol

84. A mixed triglyceride contains:
    a) three similar fatty acids esterified with glycerol
    b) two similar fatty acids esterified with glycerol
    c) three different fatty acids esterified with glycerol
    d) all of the above

C) ceramide

85. The central compound found in the structure of sphingolipids:
    a) glycerol
    b) sphingosine
    c) ceramide
    d) phosphocholine

A) tocopherol

86. Lipid whose specific test is the Furter-Meyer test:
    a) tocopherol
    b) retinol
    c) sphingomyelin
    d) cerebroside

A) ammonium phosphomolybdate

87. Precipitate of ___________ indicates the presence of phospholipids in the lipid sample:
    a) ammonium phosphomolybdate
    b) phosphorus periodate
    c) phosphorus triiodide
    d) phospho-ammonium sulfate complex

B) phosphatides

📌NOTE: Glycolipid include:

• Globoside

• Ganglioside

• Cerebrosides

88. The following are glycolipids except:
    a) globosides
    b) phosphatides
    c) gangliosides
    d) cerebrosides

B) phosphatidic acid

89. The parent compound of phospholipids:
    a) glycerol
    b) phosphatidic acid
    c) ethanolamine
    d) none of the above

D) cellobiose

90. A non-pentose sugar which is also positive for Tollen's phloroglucinol test:
    a) galactose
    b) glucose
    c) fructose
    d) cellobiose

C) sulfuric acid

91. The reagent present in Molisch test which is responsible for the dehydration reaction:
    a) sodium carbonate
    b) magnesium stearate
    c) sulfuric acid
    d) NaOH

C) iodine

92. ID test to detect the presence of glycogen:
    a) phloroglucinol
    b) Molisch
    c) iodine
    d) Seliwanoff

C) mannose

93. The only sugar that readily forms insoluble osazone crystals:
    a) lactose
    b) sucrose
    c) mannose
    d) maltose

D) chitin

94. Important structural material found in the exoskeletons of many lower animals:
    a) chondroitin
    b) heparin
    c) hyaluronic acid
    d) chitin

B) osazones

NOTE: Hydrolysis of osazones (with HCl and CuSO₄, for example) actually produces osones

95. Hydrolysis of osazones produce:
    a) phenylhydrazones
    b) osazones
    c) sugars
    d) none of the above

C) pectin

96. General term for a group of polysaccharides present in the primary cell wall:
    a) xanthan
    b) mucilage
    c) pectin
    d) carrageenan

C) mucic acid test

97. Specific test for galactose, due to the formation of highly insoluble crystals:
    a) phenylhydrazine test
    b) fermentation
    c) mucic acid test
    d) Molisch

A) mRNA

98. Type of RNA which serves as template for the amino acid sequence being synthesized:
    a) mRNA
    b) tRNA
    c) rRNA
    d) none of the above

B) blue-green color

99. Positive indication for Anthrone test:
    a) purple ring
    b) blue-green color
    c) effervescence
    d) yellow precipitate

B) iodine test

100. Differentiating test between helical and linear polysaccharides:
     a) Molisch
     b) iodine test
     c) Schweitzer's test
     d) fermentation