Structure and Properties of Amino Acids MCQs : This section focuses on the "Structure and Properties of Amino Acids". These Multiple Choice Questions (MCQs) should be practiced to improve the Structure and Properties of Amino Acids skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Question 1
Amino acids required in the human diet and not synthesized by the body are called
A. specialized
B. trace
C. essential
D. accessory
Question 2
Which pair of amino acids absorbs the most UV light at 280 nm?
A. Threonine & Histidine
B. Trp & Tyrosine
C. Cystein & Asparagine
D. Phenylalnine & Proline
Question 3
Which of the following amino acid is known as half-cystine residue?
A. Cysteine
B. Isoleucine
C. Valine
D. Histidine
Question 4
Which of the following is a nonstandard amino acid?
A. Cysteine
B. Isoleucine
C. Hydroxyproline
D. Histidine
Question 5
Which of the following pairs of amino acids would carry a negative charge on their side chain at pH 8.0?
A. Asparagine & Glutamine
B. Leucine & Glycine
C. Histidine & Lysine
D. Aspartate & Glutamate
Question 6
Which of the following amino acid contain an imidazolium moiety?
A. Alanine
B. Valine
C. Cysteine
D. Histidine
Question 7
What is the product of the catabolic breakdown of Alanine?
A. Fumarate
B. Oxaloacetate
C. Pyruvate
D. Malate
Question 8
An essential amino acid is one that
A. is essentially easy to synthesize
B. is essential to flagella motion
C. the body cannot synthesize
D. the body can synthesize under essential conditions
Question 9
Stereo chemical configuration of all a-amino acids derived from proteins is
A. L
B. D
C. L and D
D. None of these
Question 10
Serine and threonine are polar amino acids due to
A. reactive hydroxyl group in the side chain
B. reactive alcoholic group in the side chain
C. reactive keto group in the side chain
D. reactive aldehyde group in the side chain
Question 11
Proteins and macromolecular structures take on their higher order structures
A. by self-assembly
B. with the help of molecular chaperons
C. with the help of precursor sequences that are removed from the final structures
D. all of the above
Question 12
In a polypeptide average mass of an amino acid residue is
A. 110 daltons
B. 118 daltons
C. 80 daltons
D. 150 daltons
Question 13
Coomassie Blue stains the proteins by reacting with
A. arginine residues
B. free c-termini
C. peptide bonds
D. aromatic ring
Question 14
The sulphur containing side chain of cysteine is
A. ampiphillic, highly reactive and capable of reacting with another cysteine
B. hydrophillc, highly reactive and capable of reacting with another cysteine
C. hydrophobic, highly reactive and capable of reacting with another cysteine
D. none of the above
Question 15
Which of the following is an essential amino acid?
A. Tryptophan
B. Methionine
C. Lysine
D. All of these
Question 16
Which of the following is not a sensible grouping of amino acids based on their polarity properties?
A. Ala, Leu, and Val
B. Arg, His, and Lys
C. Phe, Trp, and Tyr
D. Asp, Ile, and Pro
Question 17
What is the end product of leucine metabolism?
A. Acetyl-CoA
B. Pyruvic acid
C. Oxaloacetic acid
D. Acetyl carnitine
Question 18
Which of the following is a nonprotein amino acid?
A. Dopamine
B. Hydroxylysine
C. Cystine
D. None of these
Question 19
Which amino acid when exposed to ninhydrin produces a brown color?
A. Asparagine
B. Proline
C. Alanine
D. Valine
Question 20
Which of the following is not an essential amino acid?
A. Aspartic acid
B. Glutamic acid
C. Glycine
D. All of these
Question 21
The sequence of letters 'WYQN' will represent
A. Tryptophan, tyrosine, glutamic acid, asparagine
B. Tryptophan, tyrosine, glutamine, asparagine
C. Tryptophan, glutamine, tryptophan, asparagine
D. Glutamine, tyrosine, tryptophan, aspartic acid
Question 22
The α-amino acids have a carboxyl group with a pK around __________ , and an amino group with a pK near __________ .
A. 1.1, and 12.1
B. 6.5, and 8.0
C. 3.3, and 10.5
D. 2.2, and 9.4
Question 23
Which of the following amino acids can form hydrogen bonds with their side (R) groups?
A. Asparagine
B. Aspartic acid
C. Glutamine
D. All of these
Question 24
How many different amino acids are there?
A. 3
B. 20
C. 100
D. An infinite number
Question 25
When the amino acid alanine (R-group is CH3) is added to a solution with a pH of 7.3, alanine becomes
A. a cation
B. nonpolar
C. a zwitterions
D. an isotope
Question 26
D-Alanine and L-Alanine are technically known as
A. anomers
B. enantiomers
C. epimers
D. polymer
Question 27
Protein fluorescence arises primarily from which residue?
A. Arginine
B. Tryptophan
C. Tyrosine
D. Phenylalanine
Question 28
What is the product of the catabolic breakdown of Arginine?
A. Alpha-ketoglutarate
B. Fumarate
C. Oxaloacetate
D. Succinate
Question 29
Which of the following is not the hydrophobic and aromatic amino acid?
A. Phenylalanine
B. Tyrosine
C. Tryptophan
D. None of these
Question 30
Which amino acids would most likely reside in the membrane-anchoring domain of a membrane embedded protein?
A. Isoleucine, valine and phenylalanine
B. Phenylalanine, valine, and aspartate
C. Leucine, threonine, and lysine
D. Lysine, arginine and histidine
Question 31
Molecules that bear charged groups of opposite polarity are known as
A. zwitterions
B. ambions
C. ion conversion
D. amphions
Question 32
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
Question 33
What is the heaviest of the twenty amino acids?
A. Phenylalanine
B. Tryptophan
C. Tyrosine
D. Histidine