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Proteins MCQs

Set of Important MCQs on protein chemistry for the preparation of tests for chemistry and biology. 

What is the one-letter symbol for Aspartic Acid?

  1. A
  2. T
  3. S
  4. D

Question’s Answer: D

Serine can be a precursor of all of the following, excluding?

  1. Methionine
  2. Ethanolamine
  3. Cysteine
  4. Choline

Question’s Answer: Methionine

How many high energy bonds are utilized throughout the synthesis of Urea?

  1. 2
  2. 6
  3. 4
  4. 3

Question’s Answer: 4

Which amino acids is a precursor for a number of hormones:

  1. Tyrosine
  2. Valine
  3. Alanine
  4. Histidine

Question’s Answer: Tyrosine

Oxidative conversion of amino acids to 9 their corresponding keto acids occurs in:

  1. Adipose Tissue
  2. Liver
  3. Pancreas
  4. All of these

Question’s Answer: Liver

The two nitrogens in Urea are derived form

  1. Ammonia and Glutamine
  2. Ammonia and Aspartate
  3. Glutamine and Aspartate
  4. Ammonia and glutamic acid

Question’s Answer: Ammonia and Aspartate

Which of the following is a basic amino acid?

  1. Glycine
  2. Cystine
  3. Lysine
  4. Alanine

Question’s Answer: Lysine

Glycine reacts with nitrous acid to form which of the following?

  1. Glycollic acid
  2. Acetic acid
  3. Zwitterion
  4. Methyl amine

Question’s Answer: Glycollic acid

Amino acids have which group?

  1. Basic group
  2. Acidic group
  3. Both of these
  4. None of these

Question’s Answer: Both of these

Which is proficient of forming zwitterion?

  1. Halo acids
  2. Amino acids
  3. Hydroxy acids
  4. All of these

Question’s Answer: Amino acids

Dry distillation of amino acids with barium hydroxide yields which of the following?

  1. Acids
  2. Hydroxy acids
  3. Alcohols
  4. Amines

Question’s Answer: Amines

a-Amino acids when heated alone, then  form ________.

  1. Cyclic lactum
  2. a.ß-unsaturated acid
  3. Fatty acids
  4. Diketopiperazines

Question’s Answer: Diketopiperazines

Amino acids react with _____ reagent to produce a blue colour.

  1. Ninhydrin
  2. LIAIHA
  3. CHCI/KOH
  4. Brady’s reagent

Question’s Answer: Ninhydrin

Which is a sulphur containing amino acid?

  1. Histidine
  2. Homoserine
  3. Valine
  4. Methionine

Question’s Answer: Methionine

Albumin is classified as

  1. Conjugated protein
  2. Simple protein
  3. Lipoprotein
  4. None of these

Question’s Answer: Simple protein

Which is not a common property of amino acids?

  1. They are amorphous solids
  2. They are soluble in water
  3. Their dipole moments are high
  4. They have high m.p. and B.p.

Question’s Answer: They are amorphous solids

Which reaction cannot be helpful and used for the synthesis of a-amino acids?

  1. Sorensen synthesis
  2. Streckers synthesis
  3. Gabriel phthalimide.
  4. Schmidt synthesis

Question’s Answer: Gabriel phthalimide

Primary structure of protein refers to which of the following?

  1. Arrangement of peptide chains
  2. Amino acid sequence
  3. Orientation of amino acids
  4. Whether it has a- or B-helix in space structure

Question’s Answer: Amino acid sequence

Ninhydrin test is given by which of the following?

  1. Proteins
  2. Amino acids
  3. Both proteins and amino acids
  4. None of these

Question’s Answer: Both proteins and amino acids

Molecular weight of proteins may be determined by _____.

  1. Osmotic pressure measurements
  2. Light scattering methods
  3. Sedimentation methods.
  4. All of these

Question’s Answer: All of these

Putrefaction is

  1. Hydrolysis of proteins
  2. Bacterial oxidation of proteins
  3. Reduction of proteins
  4. All of these

Question’s Answer: Bacterial oxidation of proteins

Proteins have characteristics of which of the following?

  1. Isoelectric point
  2. Melting point
  3. Boiling point
  4. All of these

Question’s Answer: Isoelectric point

What are Enzymes?

  1. Complex nonliving compounds
  2. Living organisms
  3. Bacterial colonies
  4. Complex protein molecules

Question’s Answer: Complex nonliving compounds

Trypsin, is an enzyme that can _________ .

  1. Hydrolyses proteins
  2. Hydrolyses fats
  3. Oxidizes proteins
  4. Oxidizes carbohydrates

Question’s Answer: Hydrolyses proteins

Oxidative enzymes are accountable for which of the following?

  1. Biological processes
  2. Biological hydrolysis
  3. Biological oxidations.
  4. Biological isomerization

Question’s Answer: Biological oxidations

Enzymatic action is ideal at a fixed

  1. pH
  2. Temperature
  3. Both of these
  4. None of these

Question’s Answer: Both of these

Which structure refers to the arrangement of peptide chains of protein in space to form helix structure?

  1. Secondary structure
  2. Primary structure
  3. Tertiary structure
  4. Quaternary structure

Question’s Answer: Secondary structure

Which test is not shown by proteins?

  1. Xanthoproteic test
  2. Ninhydrin test
  3. Mulliken-Barker test
  4. Hopkin-Cole test

Question’s Answer: Mulliken-Barker test

_________is the Coagulation of protein on treatment with heavy metal salts or heating.

  1. Denaturation
  2. Decolourisation
  3. Sedimentation process
  4. Reversible precipitation

Question’s Answer: Denaturation

Apoenzyme is

  1. Hydrolytic enzyme
  2. Oxidative enzyme
  3. Coenzyme
  4. Protein part of enzyme after removal of coenzyme

Question’s Answer: Protein part of enzyme after removal of coenzyme

Coenzyme can be separated from enzyme by

  1. Dialysis.
  2. Precipitation
  3. Hydrolysis
  4. Distillation

Question’s Answer: Dialysis.

An stereospecific enzyme is one which catalyzes

  1. Formation of one stereoisomer
  2. Reaction of one stereoisomer only
  3. Both of these
  4. None of these

Question’s Answer: Reaction of one stereoisomer only

Urease, an enzyme helpful and used to estimate urea is a

  1. Reductive enzyme
  2. Oxidative enzyme
  3. Hydrolytic enzyme
  4. Isomerizing enzyme

Question’s Answer: Hydrolytic enzyme

Protein tertiary structure is controlled by Which factors?

  1. Hydrophobic interactions of amino acids with nonpolar side chains
  2. The ability of the amino acid R-group to form H-group
  3. The ionic character of the amino acid R-group
  4. All of these

Question’s Answer: All of these

Digestion of protein is essentially _______

  1. Hydrolysis to a-amino acids
  2. Liberation of NH3
  3. Combination of amino acids
  4. Change in secondary structure

Question’s Answer: Hydrolysis to a-amino acids

The regular coiled arrangement produced by hydrogen bonding in proteins is known as as

  1. 6-Helix
  2. 8-Pleated Sheets
  3. a-Helix
  4. Random coils

Question’s Answer: a-Helix

The bonds that hold the tertiary structure of proteins together are:

  1. Hydrophobic bonds
  2. Peptide bonds
  3. Disulphide bonds
  4. All of these

Question’s Answer: All of these

The Positive Biuret test suggests the presence of two or more

  1. Peptide bonds
  2. Diester bonds
  3. Disulphide bonds
  4. Glycosidic bonds

Question’s Answer: Peptide bonds

Oxytocin, a pituitary hormone is

  1. Polypeptide
  2. Amino acid
  3. Protein
  4. Conjugated protein

Question’s Answer: Polypeptide

What is the isoelectric point of a protein or amino acid?

  1. pH at which it does not have any charge
  2. pH at which it does not have net charge and does not migrate in electric field
  3. pH at which the concentration of cation is greater than anion
  4. pH at which the concentration of anion is greater than cation

Question’s Answer: pH at which it does not have net charge and does not migrate in electric field

Which is a neutral amino acid with aliphatic side chain?

  1. Lysine
  2. Leucine
  3. Proline
  4. Histidine

Question’s Answer: Lysine

Which one of the following is a basic amino acid?

  1. Glycine
  2. Serine
  3. Histidine
  4. Proline

Question’s Answer: Histidine

Peptide bond formation involves removal of one molecule of:

  1. Ammonia
  2. Water
  3. Carbon dioxide
  4. A side chain of amino acid

Question’s Answer: Water

Which does the tertiary structure of a protein refer to?

  1. Amino acid sequence
  2. Amino acid composition
  3. The 3-D structure
  4. Helical structure of proteins

Question’s Answer: The 3-D structure

Many globular proteins are stable in solution although they lack in:

  1. Disulfide bonds
  2. Salt bonds
  3. Non-Polar bonds
  4. Hydrogen bonds

Question’s Answer: Disulfide bonds

Denatured collagen is known as:

  1. Melanin
  2. Tendon
  3. Gelatin
  4. Papain

Question’s Answer: Gelatin

Polymer of less than 100 amino acids is termed as:

  1. Oligopeptide
  2. Protein
  3. Peptone
  4. Polypeptide

Question’s Answer: Polypeptide

Which amino acids contains a hydroxyl group?

  1. Alanine
  2. Threonine
  3. Isoleucine
  4. Arginine

Question’s Answer: Threonine

The minimum number of ionizable groups in an amino acid are

  1. One
  2. Three
  3. Two
  4. Four

Question’s Answer: Two

Which amino acids is a precursor of catechol amines?

  1. Phenylalanine
  2. Histidine
  3. Valine
  4. Alanine

Question’s Answer: Phenylalanine

All of the following amino acids are optically active excluding:

  1. Serine
  2. Glycine
  3. Threonine
  4. Tryptophan

Question’s Answer: Glycine

What is the single letter symbol for the amino acid. “Glutamine?”

  1. Z
  2. N
  3. G
  4. Q

Question’s Answer: Q

A peptide bond.

  1. Has a partial double bond character
  2. Is ionized at physiologic pH
  3. Occurs most commonly in the is configuration
  4. All of these.

Question’s Answer: Has a partial double bond character

What is the single letter symbol for the amino acid “Phenylalanine?”

  1. P
  2. R
  3. F
  4. A

Question’s Answer: F

What is the single letter symbol for the amino acid “Lysine?”

  1. S
  2. L
  3. Y
  4. K

Question’s Answer: K

Which is an example of a chromoprotein?

  1. Giliadin
  2. Catalase
  3. Zein
  4. Salmine

Question’s Answer: Catalase

What is the single letter symbol for the amino acid “Arginine”?

  1. A
  2. G
  3. R
  4. N

Question’s Answer: R

What is the single letter symbol for the amino acid “Tryptophan”?

  1. W
  2. R
  3. Q
  4. T

Question’s Answer: W

What is the single letter symbol for the amino acid “Glutamic Acid?”

  1. D
  2. E
  3. G
  4. A

Question’s Answer: E

Which amino acids is not compatible with a-helix structure of proteins:

  1. Histidine
  2. Arginine
  3. Proline
  4. Lysine

Question’s Answer: Proline

Which is not an essential amino acid?

  1. Leucine
  2. Tyrosine
  3. Isoleucine
  4. Threonine

Question’s Answer: Tyrosine

Which one of the following statements concerning glutamine is true?

  1. One I letter symbol
  2. Is classified as an acidic amino acid
  3. Contains an amide group
  4. All of these

Question’s Answer: Contains an amide group

Which interferes with the hydrogen bonds and hence the proteins?

  1. Mercaptoethanol
  2. Uric Acid
  3. Dithiothreitol
  4. Sodium dodecyl sulphate

Question’s Answer: Sodium dodecyl sulphate

The pKa of the carboxyl groups of most of the amino acide is between:

  1. 1.5-2.5
  2. 4.5-6.5
  3. 2.5-3.5
  4. 7.6-8.3

Question’s Answer: 1.5-2.5

Which technique is helpful and used to determine the isoelectric point of a protein?

  1. Isoelectric Poising
  2. Isoelectric focusing
  3. pH Gradient gel filtration
  4. Isoelectric electrophoresis

Question’s Answer: Isoelectric focusing

______is technique that can  yields the most information about spatial characteristics of atoms in a protein?

  1. Circular Dichroism Spectroscopy
  2. Structure prediction derived from complementary DNA
  3. X-Ray Diffraction Pattern
  4. Magnetic Resonance Spectroscopy

Question’s Answer: Magnetic Resonance Spectroscopy

The main protein in hair, nails and epidermis is a

  1. Haemoprotein
  2. Keratin
  3. Nucleoprotein
  4. Metalloprotein

Question’s Answer: Keratin

Phenylalanine stabilizes the protein structure by which of the following?

  1. Electrostatic interactions
  2. Disulfide bonds
  3. Hydrophobic interactions
  4. Hydrogen bonds

Question’s Answer: Hydrophobic interactions

Which is mechanically durable and chemically unreactive protein occurring in all higher vertebrates?

  1. Keratin
  2. Melanin
  3. Fibrin
  4. Albumin

Question’s Answer: Keratin

Which statements is true?

  1. The alpha-helix can be composed of more than one polypeptide chains
  2. Beta-sheets exist only in the anti-parallel form
  3. Beta-bends often contain Proline
  4. Motifs are a type of secondary structure

Question’s Answer: Beta-bends often contain Proline

Which one of the following amino acids 84 could serve as the best buffer at pH 7.0?

  1. Histidine
  2. Arginine
  3. Serine
  4. Glutamic Acid

Question’s Answer: Histidine

Which can be helpful and used for determination of N-terminal of polypeptide?

  1. Carboxypeptidase
  2. Phenylisothiocyanate
  3. Diisopropylfluorophosphate
  4. Cyanogen bromide

Question’s Answer: Phenylisothiocyanate

The milk proteins are digested by which. enzyme in the stomach of infants:

  1. Rennin
  2. Pepsin
  3. Chymotrypsin
  4. Trypasin

Question’s Answer: Rennin

What percentage of proteins from our diet 87 is normally digested?

  1. 60-69
  2. 70-79
  3. 90-99
  4. 80-89

Question’s Answer: 90-99

Which is the coenzyme in transamination reactions?

  1. Pyridoxal Phosphate
  2. Biotin
  3. FAD
  4. NADH

Question’s Answer: Pyridoxal Phosphate

How can the excess of a particular L- amino acid affect the absorption of other amino acids?

  1. No effect
  2. Accelerates absorption of L-amino acids
  3. Retards absorption of D-amino acids
  4. Retards absorption of L-amino acids

Question’s Answer: Retards absorption of L-amino acids

Which derives its nitrogen from amino acids?

  1. Sialic acid
  2. Uric acid
  3. Choline
  4. All of these

Question’s Answer: Choline

Why does the carbohydrate rich diet induce sleep?

  1. Carbohydrate metabolism releases sufficient energy to relax the muscles.
  2. Increased TCA cycle activity provides extra a-ketoglutarate which makes neuro-inhibitory glutamate

GABA through

  1. High availability of tryptophan due to free transporters and its increased conversion to serotonin/melatonin
  2. All of these

Question’s Answer: High availability of tryptophan due to free transporters and its increased conversion to serotonin/melatonin

Which is one of the symptoms of ammonia intoxication?

  1. Constipation
  2. Blurring of vision
  3. Abdominal pain
  4. Diarrhea.

Question’s Answer: Blurring of vision

Which is the symptom of inherited disorders of urea cycle?

  1. Blurring of vision
  2. Tricorrhexic nodosa
  3. Mental Retardation
  4. All of these

Question’s Answer: All of these

Which is a major vehicle for carrying ammonia from muscle to liver?

  1. Aspartate
  2. Alanine
  3. Lysine
  4. Valine

Question’s Answer: Alanine

Ammonia is detoxified in Liver to form-

  1. Glutamine
  2. Allantoin
  3. Uric Acid
  4. None of these

Question’s Answer: Allantoin

Melanin is synthesized from:

  1. Phenylalanine
  2. Tryptophan
  3. Glycine
  4. All of these

Question’s Answer: Phenylalanine

Which is oxidized by Monoamine oxidase?

  1. Tyrosine
  2. Serotonin
  3. Glucagon
  4. Glutathione

Question’s Answer: Serotonin

The normal daily excretion of urea by a man on normal carbohydrate, fat and protein diet through urine is between.

  1. 7-9 g
  2. 20-60 g
  3. 60-100 g
  4. 120-150

Question’s Answer: 20-60 g

Which two amino acids serve as precursors for polyamines?

  1. Glycine and arginine
  2. Methionine and ornithine
  3. Glycine and methionine
  4. Glutamic acid and ornithine

Question’s Answer: Methionine and ornithine

Which two amino acids serve as precursors for cretonne in muscle tissues?

  1. Glycine and ornithine
  2. Methionine and ornithine
  3. Glycine and arginine.
  4. Glutamic acid and ornithine

Question’s Answer: Glycine and arginine

Which is not a function of glutathione?

  1. It protects hemoglobin against oxidation by hydrogen peroxide.
  2. It helps in synthesis of leukotrienes
  3. It helps in amino acid transport across the cell membrane.
  4. It helps in the synthesis of polyamines

Question’s Answer: It helps in the synthesis of polyamines

Estimation of nitrogen in proteins is noramlly carried out by which of the following method?

  1. Duma’s method
  2. Kjeldahl’s method
  3. Van Slyke method
  4. Carius method

Question’s Answer: Kjeldahl’s method

Hydrolysis of proteins provides which of the following?

  1. y-amino acids only
  2. B-amino acids only
  3. a-amino acids only
  4. A mixture of all of these

Question’s Answer: a-amino acids only

Combination of a-amino acid through which linkages results result in formation of protein

  1. Peptide linkage
  2. Glycosidic linkage
  3. Lactum linkage
  4. Ester linkage

Question’s Answer: Peptide linkage

In severe acidosis, the excretion of urea is

  1. Not changed
  2. Decreased
  3. Increased
  4. All of these

Question’s Answer: Decreased

Which a-amino acid is not proficient of exhibiting optical isomerism?

  1. Glycine
  2. Arginine
  3. Alanine
  4. Leucine

Question’s Answer: Arginine

Which of the following is an acidic amino acid?

  1. Aspartic acid
  2. Cystine
  3. Lysine
  4. Aminoacetic acid

Question’s Answer: Aspartic acid

Sanger’s reagent is

  1. Carbobenzyloxy chloride
  2. Dimethyl amino sulphonyl chloride
  3. 1-Fluoro-2,4-dinitrobenzene
  4. 2,4-Dinitrophenyl hydrazine

Question’s Answer: 1-Fluoro-2,4-dinitrobenzene

More Biochemistry MCQs

  1. Acid and Base MCQs
  2. Carbohydrate MCQs
  3. Proteins MCQs
  4. Lipids and Biomembranes MCQs
  5. Nucleic acids MCQs
  6. Metabolism of Carbohydrates MCQs
  7. Enzymes MCQs
  8. Vitamins and Hormones MCQs
  9. Bioenergetic MCQs
  10. Biotechnology MCQs
  11. Biotechnology MCQs 2
  12. Basic Biochemistry MCQs (important)
  13. CHEMISTRY MCQs From all subjects of  Chemistry
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