The peptide bond in proteins is

is planar because of steric hinderance

only found between proline residues

usually cis unless proline is the next amino acid

usually trans unless proline is the next amino acid

is planar because of steric hinderance

What is the ELISA test intended to measure?

Presence of free, circulating virus in the patient

Antibodies directed against HLA molecules

In SDS-PAGE, the protein sample is first

fractionated by electrophoresis then treated with an oxidizing agent followed by anionic detergent.

treated with a reducing agent and then with anionic detergent followed by fractionation by electrophoresis

fractionated by electrophoresis then treated with an oxidizing agent followed by anionic detergent.

treated with a oxidizing agent and then with anionic detergent followed by fractionation by electrophoresis

Excess of amino acids are

immediately used in cell respiration

Edman degradation is used for _________

Identifying C-terminal amino acids

Identifying N-terminal amino acids

Identifying C-terminal amino acids

Which of the following is the correct order of sequencing?

Sequencing, ordering and cleaving

Cleaving, sequencing and ordering

Sequencing, ordering and cleaving

Ordering, cleaving and sequencing

Ordering, sequencing and cleaving

Which of the following statements is false?

The term activity refers to the total units of enzyme in a solution

The specific activity is a measure of enzyme purity

Specific activity increases during purification of an enzyme and becomes maximal and constant when the enzyme is pure

Specific activity decreases during purification of an enzyme and becomes maximal and constant when the enzyme is pure

What best summarizes the MALDI method by which gas phase ions are produced for mass spectrometry?

Sample is heated and then bombarded by electrons

Sample is hit by a low energy xenon beam

Sample is forced through a narrow capillary tube and the solvent rapidly evaporates

Sample is embedded in a crystalline matrix and bombarded by laser beams

Sample is heated and then bombarded by electrons

Which of the following statements about column chromatography is correct?

Mobile phase is a porous solid material with appropriate chemical properties held in the column

Resolution increases as the length of the column increases

Mobile phase is a porous solid material with appropriate chemical properties held in the column

Stationary phase is a buffered solution that percolates through mobile phase

Large proteins emerge from the column sooner than small ones

The best way to determine the location of protein in the purification scheme is to measure the

changes in the refractive index

mass spectroscopy of the protein

Which of the following is the most correct?

All hydrophobic amino acids are buried when a protein folds

Charged amino acids are never buried in the interior of a protein

Charged amino acids are seldom buried in the interior of a protein

All hydrophobic amino acids are buried when a protein folds

Tyrosine is only found in the interior of proteins

Gel-filtration chromatography separates on the basis of

size using porous beads packed in a column

size and shape using porous beads packed in a column

size using porous beads packed in a column

shape using porous beads packed in a column

In isoelectric focusing, proteins are separated on the basis of their

relative content of positively charged residue only

relative content of negatively charged residue only

relative content of positively and negatively charged residue

What would happen if serum is omitted from the ELISA, but all other steps remain same?

Anti-human Ig-conjugate would bind non-specifically to the ELISA plate

Anti-human Ig-conjugate would not bind and be washed away

The OD values would be nearly the same as the assay control

Anti-human Ig-conjugate would bind non-specifically to the ELISA plate

A tripeptide has _________

3 amino acids and 3 peptide bonds

3 amino acids and 1 peptide bond

3 amino acids and 2 peptide bonds

3 amino acids and 3 peptide bonds

3 amino acids and 4 peptide bonds

During the formation of the peptide bond which of the following takes place?

Hydrogen atom is lost from its carboxyl group of one amino acid and a hydroxyl group is lost from its amino group of another amino acid

Hydroxyl group is lost from its carboxyl group of one amino acid and a hydrogen atom is lost from its amino group of another amino acid

Hydrogen atom is lost from its carboxyl group of one amino acid and a hydroxyl group is lost from its amino group of another amino acid

Hydroxyl group is lost from its carboxyl group of one amino acid and a hydroxyl group is lost from its amino group of another amino acid

Hydrogen atom is lost from its carboxyl group of one amino acid and a hydrogen atom is lost from its amino group of another amino acid

The oxygen binding curves of hemoglobin and myoglobin

allow maximum transfer of oxygen to the tissues

are a consequence of the quaternary structure of hemoglobin

Sickle cell disease is due to

a mutation in the alpha chain of Hb

a mutation in the beta chain of Hb

a mutation in the alpha chain of Hb

In hemoglobin, allosteric effects occur

for maintaining Fe in the Fe2+ state

to minimize oxygen delivery to the tissues

to maximize oxygen delivery to the tissues

Affinity chromatography deals with the

specific binding of a protein constituents for another molecule

protein - carbohydrate interaction

The isoelectric point of an amino acid is defined as the pH

where the carboxyl group is uncharged

where the molecule carries no electric charge

where the carboxyl group is uncharged

where the amino group is uncharged

of maximum electrolytic mobility

226 + Mcqs in Amino Acids Peptides and Proteins in Biochemistry Page 3 McqOptions

101.	A reaction in which organic molecules join together along with the elimination of water molecule or HCl is called
A.	addition
B.	substitution
C.	condensation
D.	evaporation
Answer» D. evaporation

Discussion

102.	The peptide bond in proteins is
A.	only found between proline residues
B.	usually cis unless proline is the next amino acid
C.	usually trans unless proline is the next amino acid
D.	is planar because of steric hinderance
Answer» D. is planar because of steric hinderance

Discussion

103.	Amino acids are not used for
A.	formation of enzymes
B.	formation of hormones
C.	repair of worn out body parts
D.	detoxication of benzoic acid
Answer» E.

Discussion

104.	What is the ELISA test intended to measure?
A.	Antibody to HIV only
B.	Antigen to HIV only
C.	Presence of free, circulating virus in the patient
D.	Antibodies directed against HLA molecules
Answer» B. Antigen to HIV only

Discussion

105.	In SDS-PAGE, the protein sample is first
A.	treated with a reducing agent and then with anionic detergent followed by fractionation by electrophoresis
B.	fractionated by electrophoresis then treated with an oxidizing agent followed by anionic detergent.
C.	treated with a oxidizing agent and then with anionic detergent followed by fractionation by electrophoresis
D.	none of the above
Answer» B. fractionated by electrophoresis then treated with an oxidizing agent followed by anionic detergent.

Discussion

106.	An oil drop with a polar coat is a metaphor referring to the three dimensional structure of
A.	fibrous proteins
B.	collagen
C.	globular proteins
D.	silk protein
Answer» D. silk protein

Discussion

107.	The heme is held in place by a bond between
A.	the Fe²⁺ and cysteine
B.	the Fe³⁺ and histidine
C.	the Fe³⁺ and cysteine
D.	the Fe²⁺ and histidine
Answer» E.

Discussion

108.	Longer chains of amino acids form polymers bonded via amide link is called
A.	peptide
B.	poly peptide
C.	amine
D.	amide
Answer» C. amine

Discussion

109.	Amine group reacts in the excess of acid to produce
A.	ammonia
B.	ammonium salts
C.	ammonium ions
D.	nitrogen
Answer» C. ammonium ions

Discussion

110.	Excess of amino acids are
A.	immediately used in cell respiration
B.	converted in proteins
C.	converted to urea
D.	converted to glycogen
Answer» D. converted to glycogen

Discussion

111.	Which of the following is Edman reagent?
A.	Phenylisothiocyanate
B.	CF₃COOH
C.	FDNB
D.	Phenylthiocarbonyl
Answer» B. CF₃COOH

Discussion

112.	Edman degradation is used for _________
A.	Identifying N-terminal amino acids
B.	Identifying C-terminal amino acids
C.	Identifying amino acid
D.	Identifying carbohydrates
Answer» B. Identifying C-terminal amino acids

Discussion

113.	Which of the following is the correct order of sequencing?
A.	Cleaving, sequencing and ordering
B.	Sequencing, ordering and cleaving
C.	Ordering, cleaving and sequencing
D.	Ordering, sequencing and cleaving
Answer» B. Sequencing, ordering and cleaving

Discussion

114.	Which of the following statements is false?
A.	The term activity refers to the total units of enzyme in a solution
B.	The specific activity is a measure of enzyme purity
C.	Specific activity increases during purification of an enzyme and becomes maximal and constant when the enzyme is pure
D.	Specific activity decreases during purification of an enzyme and becomes maximal and constant when the enzyme is pure
Answer» E.

Discussion

115.	What best summarizes the MALDI method by which gas phase ions are produced for mass spectrometry?
A.	Sample is hit by a low energy xenon beam
B.	Sample is forced through a narrow capillary tube and the solvent rapidly evaporates
C.	Sample is embedded in a crystalline matrix and bombarded by laser beams
D.	Sample is heated and then bombarded by electrons
Answer» D. Sample is heated and then bombarded by electrons

Discussion

116.	Amino acids that is secondary among these is
A.	Ala
B.	Pro
C.	Gln
D.	Try
Answer» C. Gln

Discussion

117.	Which of the following is not the classified form of conjugated proteins?
A.	Lipoproteins
B.	Glycoproteins
C.	Metalloproteins
D.	Complete proteins
Answer» E.

Discussion

118.	Which of the following statements about column chromatography is correct?
A.	Resolution increases as the length of the column increases
B.	Mobile phase is a porous solid material with appropriate chemical properties held in the column
C.	Stationary phase is a buffered solution that percolates through mobile phase
D.	Large proteins emerge from the column sooner than small ones
Answer» B. Mobile phase is a porous solid material with appropriate chemical properties held in the column

Discussion

119.	An average polypeptide chain may contain up to
A.	300 amino acids
B.	400 amino acids
C.	500 amino acids
D.	more than 500 amino acids
Answer» D. more than 500 amino acids

Discussion

120.	On addition of alkali, zwitterion ion will reform
A.	amine
B.	carboxylic group
C.	alcohol
D.	carbonic acid
Answer» B. carboxylic group

Discussion

121.	The best way to determine the location of protein in the purification scheme is to measure the
A.	rate of ATP synthesis
B.	changes in the refractive index
C.	UV absorption
D.	mass spectroscopy of the protein
Answer» B. changes in the refractive index

Discussion

122.	Proteins are found in
A.	hair
B.	skin
C.	tendons
D.	all of above
Answer» E.

Discussion

123.	Ion which carries two charges, positive and negative is called
A.	azonium ion
B.	zwitterions ion
C.	uranium ion
D.	plutonium ion
Answer» C. uranium ion

Discussion

124.	Which of the following is the most correct?
A.	Charged amino acids are never buried in the interior of a protein
B.	Charged amino acids are seldom buried in the interior of a protein
C.	All hydrophobic amino acids are buried when a protein folds
D.	Tyrosine is only found in the interior of proteins
Answer» C. All hydrophobic amino acids are buried when a protein folds

Discussion

125.	Gel-filtration chromatography separates on the basis of
A.	size and shape using porous beads packed in a column
B.	size using porous beads packed in a column
C.	shape using porous beads packed in a column
D.	none of the above
Answer» B. size using porous beads packed in a column

Discussion

126.	Proteins are the natural
A.	polymers
B.	non-absorbents
C.	absorbents
D.	non-polymers
Answer» B. non-absorbents

Discussion

127.	Amino acids which are not made by enzymes in our body are called
A.	essential amino acids
B.	non-essential amino acids
C.	polymers
D.	monomers
Answer» B. non-essential amino acids

Discussion

128.	Agarose a porous matrix used in various molecular biology technique is made by repetitive units of
A.	maltose
B.	agarobiose
C.	agar
D.	none of these
Answer» B. agarobiose

Discussion

129.	In isoelectric focusing, proteins are separated on the basis of their
A.	relative content of positively charged residue only
B.	relative content of negatively charged residue only
C.	size
D.	relative content of positively and negatively charged residue
Answer» E.

Discussion

130.	Buried hydrophobic side chains in a globular protein fit into a hole formed by the side chains of
A.	1-3 other amino acids
B.	5-7 other amino acids
C.	9-12 other amino acids
D.	13-15 other amino acids
Answer» C. 9-12 other amino acids

Discussion

131.	What would happen if serum is omitted from the ELISA, but all other steps remain same?
A.	Anti-human Ig-conjugate would not bind and be washed away
B.	The OD values would be nearly the same as the assay control
C.	Both (a) and (b)
D.	Anti-human Ig-conjugate would bind non-specifically to the ELISA plate
Answer» D. Anti-human Ig-conjugate would bind non-specifically to the ELISA plate

Discussion

132.	The group which may vary in different amino acids is
A.	R-group
B.	P-group
C.	S-group
D.	N-group
Answer» B. P-group

Discussion

133.	Two chains of amino acids in an insulin molecule are held together by __________
A.	Sulfide bridges
B.	Disulfide bridges
C.	Peptide bond
D.	Covalent linkage
Answer» C. Peptide bond

Discussion

134.	A tripeptide has _________
A.	3 amino acids and 1 peptide bond
B.	3 amino acids and 2 peptide bonds
C.	3 amino acids and 3 peptide bonds
D.	3 amino acids and 4 peptide bonds
Answer» C. 3 amino acids and 3 peptide bonds

Discussion

135.	Which of the following is a 39-residue hormone of the anterior pituitary gland?
A.	Corticotropin
B.	Glucagon
C.	Insulin
D.	Bradykinin
Answer» B. Glucagon

Discussion

136.	During the formation of the peptide bond which of the following takes place?
A.	Hydroxyl group is lost from its carboxyl group of one amino acid and a hydrogen atom is lost from its amino group of another amino acid
B.	Hydrogen atom is lost from its carboxyl group of one amino acid and a hydroxyl group is lost from its amino group of another amino acid
C.	Hydroxyl group is lost from its carboxyl group of one amino acid and a hydroxyl group is lost from its amino group of another amino acid
D.	Hydrogen atom is lost from its carboxyl group of one amino acid and a hydrogen atom is lost from its amino group of another amino acid
Answer» B. Hydrogen atom is lost from its carboxyl group of one amino acid and a hydroxyl group is lost from its amino group of another amino acid

Discussion

137.	The oxygen binding curves of hemoglobin and myoglobin
A.	allow maximum transfer of oxygen to the tissues
B.	are a consequence of the quaternary structure of hemoglobin
C.	both (a) and (b)
D.	are identical
Answer» D. are identical

Discussion

138.	Beta pleated sheets are examples of protein's
A.	primary structure
B.	secondary structure
C.	tertiary structure
D.	quaternary structure
Answer» C. tertiary structure

Discussion

139.	Which of the following is an immunodiffusion test?
A.	Double-diffusion
B.	Gel diffusion
C.	Ouchterloney technique
D.	All of these
Answer» E.

Discussion

140.	A protein that binds two ligands in a non-cooperative manner will show
A.	a sigmodial binding curve
B.	a hyperbolic binding curve
C.	a linear Scatchard Plot
D.	both (b) and (c)
Answer» E.

Discussion

141.	Sickle cell disease is due to
A.	a mutation in the beta chain of Hb
B.	a mutation in the alpha chain of Hb
C.	infection with a parasite
D.	none of the above
Answer» B. a mutation in the alpha chain of Hb

Discussion

142.	In hemoglobin, allosteric effects occur
A.	only in humans
B.	for maintaining Fe in the Fe2+ state
C.	to minimize oxygen delivery to the tissues
D.	to maximize oxygen delivery to the tissues
Answer» E.

Discussion

143.	Affinity chromatography deals with the
A.	specific binding of a protein constituents for another molecule
B.	protein - protein interaction
C.	protein - carbohydrate interaction
D.	none of the above
Answer» B. protein - protein interaction

Discussion

144.	Which of the following is not an essential amino acid?
A.	Aspartic acid
B.	Glutamic acid
C.	Glycine
D.	All of these
Answer» E.

Discussion

145.	The isoelectric point of an amino acid is defined as the pH
A.	where the molecule carries no electric charge
B.	where the carboxyl group is uncharged
C.	where the amino group is uncharged
D.	of maximum electrolytic mobility
Answer» B. where the carboxyl group is uncharged

Discussion

146.	The major element of secondary structure in myoglobin and hemoglobin is
A.	the P-strand
B.	the a-helix
C.	the reverse turn
D.	All of these
Answer» C. the reverse turn

Discussion

147.	Enzymes, antibodies, and hormones are the basic needs for
A.	proteins
B.	calcium
C.	vitamin
D.	salts
Answer» B. calcium

Discussion

148.	A purified protein sample contains 10 μg of protein and has an enzyme activity of 1 m mole of ATP synthesized/sec (1 unit). What is the specific activity of the final purified sample?
A.	1,000 units/mg
B.	10,000 units/mg.
C.	100,000 units/mg
D.	1,000,000 units/mg
Answer» D. 1,000,000 units/mg

Discussion

149.	Which of the following may be added to stabilize the protein after yeast cells disruption?
A.	NaCl
B.	Protease inhibitor
C.	AMP
D.	All of these
Answer» E.

Discussion

150.	Which of the following is a nonstandard amino acid?
A.	Cysteine
B.	Isoleucine
C.	Hydroxyproline
D.	Histidine
Answer» D. Histidine

Discussion

Explore topic-wise MCQs in Biochemistry.

A reaction in which organic molecules join together along with the elimination of water molecule or HCl is called

The peptide bond in proteins is

Amino acids are not used for

What is the ELISA test intended to measure?

In SDS-PAGE, the protein sample is first

An oil drop with a polar coat is a metaphor referring to the three dimensional structure of

The heme is held in place by a bond between

Longer chains of amino acids form polymers bonded via amide link is called

Amine group reacts in the excess of acid to produce

Excess of amino acids are

Which of the following is Edman reagent?

Edman degradation is used for _________

Which of the following is the correct order of sequencing?

Which of the following statements is false?

What best summarizes the MALDI method by which gas phase ions are produced for mass spectrometry?

Amino acids that is secondary among these is

Which of the following is not the classified form of conjugated proteins?

Which of the following statements about column chromatography is correct?

An average polypeptide chain may contain up to

On addition of alkali, zwitterion ion will reform

The best way to determine the location of protein in the purification scheme is to measure the

Proteins are found in

Ion which carries two charges, positive and negative is called

Which of the following is the most correct?

Gel-filtration chromatography separates on the basis of

Proteins are the natural

Amino acids which are not made by enzymes in our body are called

Agarose a porous matrix used in various molecular biology technique is made by repetitive units of

In isoelectric focusing, proteins are separated on the basis of their

Buried hydrophobic side chains in a globular protein fit into a hole formed by the side chains of

What would happen if serum is omitted from the ELISA, but all other steps remain same?

The group which may vary in different amino acids is

Two chains of amino acids in an insulin molecule are held together by __________

A tripeptide has _________

Which of the following is a 39-residue hormone of the anterior pituitary gland?

During the formation of the peptide bond which of the following takes place?

The oxygen binding curves of hemoglobin and myoglobin

Beta pleated sheets are examples of protein's

Which of the following is an immunodiffusion test?

A protein that binds two ligands in a non-cooperative manner will show

Sickle cell disease is due to

In hemoglobin, allosteric effects occur

Affinity chromatography deals with the

Which of the following is not an essential amino acid?

The isoelectric point of an amino acid is defined as the pH

The major element of secondary structure in myoglobin and hemoglobin is

Enzymes, antibodies, and hormones are the basic needs for

A purified protein sample contains 10 μg of protein and has an enzyme activity of 1 m mole of ATP synthesized/sec (1 unit). What is the specific activity of the final purified sample?

Which of the following may be added to stabilize the protein after yeast cells disruption?

Which of the following is a nonstandard amino acid?