Which of the following features are associated with cysteine amino acid?

Which of the following amino acids have these given features? a. It has got an aliphatic carbon chain. b. It has sulphur atom. c. It has 5 carbon. d. It has 1 nitrogen atom in its structure.

Which of the following Posttranslational Modifications (PTM) leads to highest increase in molecular weight?

Which of the following atoms is replaced by selenium in cysteine amino acid to form selenocysteine?

The imidazole group of amino acid A and the guanidino group of amino acid B exist as resonance hybrids with positive charge distributed between both nitrogens in form A or all three nitrogens in form B. Write the names of the amino acids A and B.

Given: pK₁ = 2.0, pK₂ = 9.9 and pK₃ = 3.9 From the information, calculate the isoelectric pH (pI) of Aspartic acid.

Given: pK₁ (alpha-COOH) = 2.4 and pK₂ (alpha-NH₂⁺) = 9.8 From the information, calculate the isoelectric pH (pI) of Glycine.

Which of the following statements is/are correct?

1. Both L-amino acids and D-amino acids occur in nature.
2. Only D-alpha-amino acids are present in proteins.
3. All amino acids possess at least two weakly acidic functional groups, R-NH₃⁺ and R-COOH.
4. Amino acids do not possess any type of additional weakly acidic functional groups.

Which of the following statements is/are correct?

1. The pKa values of all functional groups of an amino acid dictate its net molecular at a given pH.
2. pI is the pH at which an amino acid bears only negative charge and thus moves towards cathode in applied electrical field.
3. Of the biochemical reactions of amino acids, the most important is the formation of peptide bonds.

What is the expected order of bond energy of the following bong types? O-O, S-S, C-N, S-H, C=C, C=N, C=O

Which of the following statements is/are correct?

1. Amino acids are classified based on the properties of their R groups.
2. Peptides are named for the number of amino acid residues present, and as derivatives of the carboxyl terminal residue.
3. The partial double-bond character of the bond restricts the number of possible peptide conformations.

Which of the following statements is/are correct about stationary phase in column chromatography?

1. In column chromatography of proteins, cellulose is used as stationary phase.
2. The stationary phase is packed in a metallic column.
3. The stationary phase matrices interaction is hydrophobic.

Which is correct regarding partition chromatography?

1. Association between each protein and the matrix is very strong.
2. Proteins that interact more strongly with the stationary phase are retained longer.
3. The time of protein association with the stationary phase depend only on mobile phases.

Which of the following amino acids have 5 methyl groups, no functional group and no aromatic chain?

On the basis of this fact, what is the correct decreasing order of the pKa range of various dissociating groups?

The acid strengths of weak acids are expressed as their pKa. The net charge on an amino acid is the algebraic sum of all the positively and negatively charged groups present.