Amino Acids and Proteins Multiple Choice Questions (MCQs) & Answers

Amino Acids and Proteins Multiple Choice Questions(MCQs) & Answers Amino Acids and Proteins

Amino Acids and Proteins Multiple Choice Questions(MCQs)& Answers

CONCEPTS & THEORIES

amino-acids-and-proteins

About Amino Acids and Proteins


Amino acids are organic compounds that contain amine (-NH2) and carboxyl (-COOH) functional groups, along with a side chain (R group) specific to each amino acid.Amino acids play central roles both as building blocks of proteins and as intermediates in metabolism. The 20 amino acids that are found within proteins convey a vast array of chemical versatility.

Proteins are among the most abundant organic molecules in living systems and are way more diverse in structure and function than other classes of macromolecules. A single cell can contain thousands of proteins, each with a unique function. Although their structures, like their functions, vary greatly, all proteins are made up of one or more chains of amino acids.

Essential amino acids


Humans can produce 10 of the 20 amino acids. The others must be supplied in the food. Failure to obtain enough of even 1 of the 10 essential amino acids, those that we cannot make, results in degradation of the body’s proteins—muscle and so forth—to obtain the one amino acid that is needed. Unlike fat and starch, the human body does not store excess amino acids for later use—the amino acids must be in the food every day.

Acid-Base Properties


Another important feature of free amino acids is the existence of both a basic and an acidic group at the α-carbon. Compounds such as amino acids that can act as either an acid or a base are called amphoteric.


QUESTIONS

Amino Acids and Proteins Multiple Choice Questions(MCQs)& Answers

1 What is the molecular weight of Glycine?
A 75 g•mol−1
B 80 g•mol−1
C 90 g•mol−1
D 95 g•mol−1

Answer: 75 g•mol−1
2 Which of the following is not an essential amino acid?
A Proline
B Histidine
C Leucine
D Methionine

Answer: Proline
3 Histones are rich in__________.
A Lysine
B Arginine
C Histidine
D Lysine and Arginine

Answer: Lysine and Arginine
4 Which of the following amino acid is sweet in taste?
A Glycine
B Alanine
C Glutamic acid
D None of these

Answer: Glycine
5 Which of the following amino acid act as inhibitory neurotransmitter?
A Glycine
B Alanine
C GABA
D All of these

Answer: All of these
6 The amino acid commonly used as an ingredient in the buffers of SDS PAGE.
A Aspartic acid
B Glutamic acid
C Glycine
D Aspartic acid and Lysine together

Answer: Glycine
7 Which of the following amino acid will be absent in α (alpha) helix structure of protein?
A Proline
B Glycine
C Galine
D Glutamic acid

Answer: Proline
8 Which amino acid act as the precursor of nucleotide biosynthesis?
A Aspartate
B Glycine
C Glutamine
D All of these

Answer: All of these
9 Which of the following amino acid act as excitatory neurotransmitter?
A Glutamate
B Aspartate
C Cysteine
D All of these

Answer: All of these
10 How many amino acid residues are there in per turn of α-helix?
A 3.6
B 4.6
C 3.0
D 2.5

Answer: 3.6
11 How is the secondary structure of a protein stabilized?
A Van der wall forces
B Hydrogen bonding
C Covalent bond
D Hydrophobic bond

Answer: Hydrogen bonding
12 What is the maximum wavelength that Tryptophan and tyrosine absorb?
A 280nm
B 260nm
C 257nm
D 230nm

Answer: 280nm
13 In which amino acid Imidazole group, an aromatic ring found?
A Lysine
B Arginine
C Histidine
D Glutamate

Answer: Histidine
14 Which of these are rare amino acid in a protein?
A Leucine and serine
B Lysine and glutamic acid
C Tryptophan and methionine
D Leucine and lysine

Answer: Tryptophan and methionine
15 The two amino acids having R groups with a negative net charge at pH 7.0 are
A Aspartate and glutamate
B Arginine and histidine
C Cysteine and methionine
D Proline and valine

Answer: Aspartate and glutamate
16 Identify the amino acids containing nonpolar, aliphatic R groups
A Phenylalanine, tyrosine, and tryptophan
B Glycine, alanine, leucine
C Lysine, arginine, histidine
D Serine, threonine, cysteine

Answer: Glycine, alanine, leucine
17 Among the 20 standard proteins coding amino acids, which one is least occurs in proteins?
A Glycine
B Alanine
C Tryptophan
D Methionine

Answer: Tryptophan
18 Which of the following is an example for a bio-plastic?
A Polyaspartate
B Polyglutamate
C Poly-L-lysine
D All of these

Answer: Polyaspartate
19 Bacteria prefer to use the codon CGA instead of AGA to code for Arginine. This is an example for _____.
A Second genetic code
B Nullomers
C Transcriptional decoding
D Allomers

Answer: Nullomers
20 Name the amino acid, which exists in two non-superimposable mirror images of each other.
A Epimer
B Anomer
C Enantiomer
D Chiral carbon

Answer: Enantiomer
21 A solution of L-alanine (4.0g/50 ml of 6 N HCl) has a rotation of +1.61° in a 2dm polarimeter tube. Calculate the specific rotation of L-alanine in 6 N HCl.
A +15.1°
B +10.1°
C +11.1°
D +16.1°

Answer: +10.1°
22 Which of these are used to measure optical activity?
A Polarimeter
B Planometer
C Psychrometer
D Photometer

Answer: Polarimeter
23 Which among the following is both glucogenic and ketogenic?
A Isoleucine
B Leucine
C Lysine
D Histidine

Answer: Isoleucine
24 Which of the following is an imino acid?
A Alanine
B Glycine
C Proline
D Serine

Answer: Proline
25 Which of the following is an essential amino acid?
A Cysteine
B Asparagine
C Glutamine
D Phenylalanine

Answer: Phenylalanine
26 Which among the following is a non-essential amino acid?
A Serine
B Threonine
C Lysine
D Histidine

Answer: Serine
27 Which of the following is a true statement?
A Tryptophan and tyrosine are significantly more polar than phenylalanine
B Leucine is commonly used as an ingredient in the buffers of SDS page
C Aspartate is an essential amino acid
D Lysine is a non-essential amino acid

Answer: Tryptophan and tyrosine are significantly more polar than phenylalanine
28 If pK1 = 2.34 and pK2 = 9.60, then the isoelectric point pI is
A 5.87
B 5.97
C 3.67
D 11.94

Answer: 5.97
29 Which of these amino acids are not optically active?
A Cysteine
B Lysine
C Arginine
D Glycine

Answer: Glycine
30 The general structure of all amino acids are same except for ___________
A Lysine
B Glycine
C Proline
D Alanine

Answer: Proline

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