MCQS | In a polypeptide average mass of an amino acid residue is

Question :- Protein fluorescence arises primarily from which residue?

1.Arginine

2.Tryptophan

3.Tyrosine

4.Phenylalanine

Question :- Which of the following is an essential amino acid?

1.Tryptophan

2.Methionine

3.Lysine

4.All of these

Question :- The sulphur containing side chain of cysteine is

1.ampiphillic, highly reactive and capable of reacting with another cysteine

2.hydrophillc, highly reactive and capable of reacting with another cysteine

3.hydrophobic, highly reactive and capable of reacting with another cysteine

4. none of the above

Question :- Amino acids required in the human diet and not synthesized by the body are called

1.specialized

2.trace

3.essential

4.accessory

Question :- An essential amino acid is one that

1. is essentially easy to synthesize

2.is essential to flagella motion

3.the body cannot synthesize

4.the body can synthesize under essential conditions

Question :- Coomassie Blue stains the proteins by reacting with

1.arginine residues

2.free c-termini

3.peptide bonds

4. aromatic ring

Question :- D-Alanine and L-Alanine are technically known as

1.anomers

2.enantiomers

3.epimers

4.polymer

Question :- How many different amino acids are there?

1.3

2.20

3.100

4. An infinite number

Question :- In a polypeptide average mass of an amino acid residue is

1.110 daltons

2.118 daltons

3.80 daltons

4.150 daltons

Question :- Molecules that bear charged groups of opposite polarity are known as

1.zwitterions

2.ambions

3.ion conversion

4.amphions

Question :- Proteins and macromolecular structures take on their higher order structures

1.by self-assembly

2.with the help of molecular chaperons

3.with the help of precursor sequences that are removed from the final structures

4. all of the above

Question :- Serine and threonine are polar amino acids due to

1.reactive hydroxyl group in the side chain

2.reactive alcoholic group in the side chain

3.reactive keto group in the side chain

4.reactive aldehyde group in the side chain

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

1.L

2.D

3.L and D

4.None of these

Question :- The α-amino acids have a carboxyl group with a pK around __________ , and an amino group with a pK near __________ .

1.1.1, and 12.1

2. 6.5, and 8.0

3.3.3, and 10.5

4. 2.2, and 9.4

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

1.where the molecule carries no electric charge

2. where the carboxyl group is uncharged

3.where the amino group is uncharged

4.of maximum electrolytic mobility

Question :- The sequence of letters 'WYQN' will represent

1.Tryptophan, tyrosine, glutamic acid, asparagine

2.Tryptophan, tyrosine, glutamine, asparagine

3.Tryptophan, glutamine, tryptophan, asparagine

4. Glutamine, tyrosine, tryptophan, aspartic acid

Question :- What is the end product of leucine metabolism?

1.Acetyl-CoA

2.Pyruvic acid

3.Oxaloacetic acid

4. Acetyl carnitine

Question :- What is the heaviest of the twenty amino acids?

1.Phenylalanine

2.Tryptophan

3.Tyrosine

4.Histidine

Question :- What is the product of the catabolic breakdown of Alanine?

1.Fumarate

2.Oxaloacetate

3.Pyruvate

4.Malate

Question :- What is the product of the catabolic breakdown of Arginine?

1.Alpha-ketoglutarate

2. Fumarate

3.Oxaloacetate

4.Succinate

Question :- When the amino acid alanine (R-group is CH3) is added to a solution with a pH of 7.3, alanine becomes

1.an isotope

2.a cation

3.nonpolar

4.a zwitterions

Question :- Which amino acid when exposed to ninhydrin produces a brown color?

1.Asparagine

2.Proline

3.Alanine

4.Valine

Question :- Which amino acids would most likely reside in the membrane-anchoring domain of a membrane embedded protein?

1.Isoleucine, valine and phenylalanine

2.Phenylalanine, valine, and aspartate

3. Leucine, threonine, and lysine

4. Lysine, arginine and histidine

Question :- Which of the following amino acid contain an imidazolium moiety?

1.Alanine

2.Valine

3.Cysteine

4.Histidine

Question :- Which of the following amino acid is known as half-cystine residue?

1.Cysteine

2.Isoleucine

3.Valine

4.Histidine

Question :- Which of the following amino acids can form hydrogen bonds with their side (R) groups?

1.Asparagine

2.Aspartic acid

3.Glutamine

4.All of these

Question :- Which of the following is a nonprotein amino acid?

1.Dopamine

2.Hydroxylysine

3.Cystine

4. none of the these

Question :- Which of the following is a nonstandard amino acid?

1.Cysteine

2.Isoleucine

3.Hydroxyproline

4.Histidine

Question :- Which of the following is not a sensible grouping of amino acids based on their polarity properties?

1.Ala, Leu, and Val

2. Arg, His, and Lys

3.Phe, Trp, and Tyr

4.Asp, Ile, and Pro

Question :- Which of the following is not an essential amino acid?

1.Aspartic acid

2.Glutamic acid

3.Glycine

4. All of these

Question :- Which of the following is not the hydrophobic and aromatic amino acid?

1.Phenylalanine

2.Tyrosine

3.Tryptophan

4. none of the these

Question :- Which of the following pairs of amino acids would carry a negative charge on their side chain at pH 8.0?

1.Asparagine & Glutamine

2.Leucine & Glycine

3.Histidine & Lysine

4.Aspartate & Glutamate

Question :- Which pair of amino acids absorbs the most UV light at 280 nm?

1.Threonine & Histidine

2.Trp & Tyrosine

3.Cystein & Asparagine

4.Phenylalnine & Proline