Amino Acids

Q. The non-essential amino acid among the following is:

1. Valine
2. Leucine
   
3. Alanine
4. Lysine

Q. SiO is acidic or basic

Q. An enzyme contains 5.6% Fe. Calculate number of Fe atoms present in 1gm of this enzyme.

Q. which is actually the alpha carbon? is it the functional group attached one or the carbon next to i

Q. The increasing order of $p{k}_a$ for the following amino acids (Gly, Asp, Lys, Arg) in aqueous solution is:

1. Asp<Gly<Arg<Lys
2. Arg<Lys<Gly<Asp
3. Gly<Asp<Arg<Lys
4. Asp<Gly<Lys<Arg

Q.

Which one of the following is the strongest acid ?

1. Cl₂CH COOH

2. ClCH₂ COOH

3. CH₃ COOH

4. Cl₃CCOOH

Q.

The number of tripeptides formed by 3 different amino acids is:

1. Five

2. Six

3. Three

4. Four

Q.

In alkaline medium, glycine predominantly exists as/in a/an:

1. Cation

2. Anion

3. Zwitter ion

4. Covalent form

Q.

Nature of aqueous solutions of two different amino acids 'X' and 'Y' are acidic and basic. Here 'X' and 'Y' are

1. Alanine and valine

2. Aspartic acid and asparagine

3. Glutamine and Glutamic acid

4. Aspartic acid and lysine

Q. 0.1 M each of 3 salt solutions of NaX, NaY and NaZ has pH=8, 9, 10.Arrange in the acidic strength for H, HYand HZ

Q. 49 What is the order of stability among following acids . hclo, hclo2, Hclo3, hclo4.

Q. Between FCH2COOH and C6H5COOH , which is more acidic

Q. A decapeptide (Mol. Wt. 796) on complete hydrolysis gives glycine (Mol. Wt. 75), alanine and phenylalanine. Glycine contributes 47.0% to the total weight of the hydrolysed products. The number of glycine units present in the decapeptide is ___.
(IIT-JEE, 2011)

Q.

The wrong statement about the isoelectric point is:

1. Amino acid is present as zwitter ion
2. Amino acids have high solubility
3. Amino acid can be separated from the solution
4. They do not migrate in electrical field

Q.

Which of the following statements is correct with respect to all amino acids? They are:

1. All optically active

2. All optically active, except glycine

3. All optically active, except lysine

4. All optically active except glutamic acid

Q. The $p{K}_a$ values for the three ionisable groups $X,Y\text{and}Z$ of glutamic acid are 4.3, 9.7 and 2.2 respectively.

The isoelectric point for the amino acid is:

1. 7
2. 3.25
3. 4.95
4. 5.95

Q.

Which of the nitrogen of histidine is first protonated ?

1. $\alpha$

2. $\beta$

3. $Both$

4. $None$

Q. Thiol group is present in

1. Cystine
2. Cysteine
3. Methionine
4. Cytosine

Q. 23.Molarity of 200ml of 18.25N of NaOH will be 1)32.5M 2)91.25M 3)2.38M 4)22.8M

Q. 5. 0.1 m formic acid gets 1 % ionize if it is ionized 10 % its concentration will be a)0.001 b)0.01 c)0.0001 d)0.1

Q. A tetrapeptide has -COOH group on alanine. This produces glycine (Gly), valine (Val), phenyl alanine (Phe) and alanine (Ala), on complete hydrolysis. For this tetrapeptide, the number of possible sequences (Primary structures) with - NH₂ group attached to a chiral centre is___

Q.

What is the following is a basic amino acid?

1. Lysine

2. Proline

3. Alanine

4. Aspartic acid

Q. $\underset{\left(C_3{H}_{7}N{O}_3\right)}{\left(A\right)\alpha -\text{Amino acid}}\underset{HCl}{\overset{MeOH}{\to }}\underset{\left(C_4{H}_{10}N{O}_{3}Cl\right)}{\left(B\right)}\stackrel{PC{l}_5}{\to }\underset{\left(C_4{H}_{9}N{O}_{2}C{l}_2\right)}{\left(C\right)}$

$\underset{\left(C_4{H}_{9}N{O}_{2}C{l}_2\right)}{\left(C\right)}\stackrel{H_3{O}^{+}}{\to }\underset{\left(C_3{H}_{6}N{O}_{2}Cl\right)}{\left(D\right)}\underset{HCl}{\overset{Na-Hg}{\to }}\text{Alanine}$

Compound (D) is :

1. 
2. 
3. 
4. Both (b) and (c)

Q.

Which of the following dipolar structure of the amino acid is considered to be more correct ?

1. 

2. 

3. Both

4. None

Q.

The α - amino acids, usually exist in the form of zwitter ions. It means they have:

1. No acidic or basic group

2. Basic group - COO^- and acidic group NH₄⁺

3. Basic group -COO^- and acidic group - NH₃⁺

4. Basic group - COO^- and acidic group - COO^2-

Q.

The ionization constant of acetic acid is 1.74 × 10. Calculate the degree of

dissociation of acetic acid in its 0.05 M solution. Calculate the concentration of acetate ion in the solution and its pH.

Q.

Leucine is a/an ________ amino acid.

1. essential

2. non-essential

3. aromatic

4. acidic

Q.

The ionization constant of nitrous acid is 4.5 × 10^–4. Calculate the pH of 0.04 M sodium nitrite solution and also its degree of hydrolysis.

Q. ${\mathrm{Pk}}_a\mathrm{and}{\mathrm{Pk}}_b\mathrm{values}\mathrm{of}\mathrm{isoleucine}\mathrm{is}2.36\mathrm{and}9.68\mathrm{respectively}.\mathrm{Then}{P}_I=?$

1. 2.36
2. 9.68
3. 6.02
4. 3.66

Q. Which of the following $\alpha$ - amino acids is not optically active?

1. Alanine
2. Glycine
3. Phenylalanine
4. Cysteine