MCQs BIOCHEMISTRY: Properties of amino acids

1. Protein fluorescence arises primarily from which residue?

A. Arginine B. Tryptophan
C. Tyrosine D. Phenylalanine
Answer & Explanation
Answer: Option B


2. Which of the following amino acid is known as half-cystine residue?

A. Cysteine B. Isoleucine
C. Valine D. Histidine
Answer & Explanation
Answer: Option A

3. Which of the following is not an essential amino acid?

A. Aspartic acid
B. Glutamic acid
C. Glycine
D. All of these
Answer & Explanation
Answer: Option D


4. 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
Answer & Explanation
Answer: Option D


5. 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
Answer & Explanation
Answer: Option D


6. What is the product of the catabolic breakdown of Alanine?

A. Fumarate B. Oxaloacetate
C. Pyruvate D. Malate
Answer & Explanation
Answer: Option C

7. How many different amino acids are there?

A. 3
B. 20
C. 100
D. An infinite number
Answer & Explanation
Answer: Option B

8.
Amino acids required in the human diet and not synthesized by the body are called

A. specialized B. trace
C. essential D. accessory
Answer & Explanation
Answer: Option C

9.
Which of the following amino acid contain an imidazolium moiety?

A. Alanine B. Valine
C. Cysteine D. Histidine
Answer & Explanation
Answer: Option D

10.

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
Answer & Explanation
Answer: Option B

11.
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
Answer & Explanation
Answer: Option C

12.
Which of the following is a nonprotein amino acid?

A. Dopamine
B. Hydroxylysine
C. Cystine
D. None of these
Answer & Explanation
Answer: Option A


13.
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
Answer & Explanation
Answer: Option A

14.
Which of the following is not the hydrophobic and aromatic amino acid?

A. Phenylalanine
B. Tyrosine
C. Tryptophan
D. None of these
Answer & Explanation
Answer: Option D

15.

Stereo chemical configuration of all a-amino acids derived from proteins is

A. L
B. D
C. L and D
D. None of these
Answer & Explanation
Answer: Option A