Question

The correct statements about peptides are:

• A. A dipeptide has one peptide link between two amino acids
• B. By convention $N$-Termius is kept at left and $C$-terminus at right in the structure of a peptide
• C. If only one amino group and one carboxylic acid group are available for reaction, then only one dipeptide can form
• D. A polypeptide with more than hundred amino acid residues
  (Molar mass > 10000) is called a protein

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A A dipeptide has one peptide link between two amino acids
B By convention $N$-Termius is kept at left and $C$-terminus at right in the structure of a peptide
C If only one amino group and one carboxylic acid group are available for reaction, then only one dipeptide can form
D A polypeptide with more than hundred amino acid residues

(Molar mass > 10000) is called a protein
A) Peptide linkage is an amide formed between –$COOH$ group and –$N{H}_2$ group. When a carboxyl group of one amino acid combines with the amino group of another amino acid we get a dipeptide. So a dipeptide has one peptide link between two amino acids.

B) Conventionally $N$-Terminus is kept at left and $C$- terminus at right in the structure of a peptide.

C) When a carboxyl group of one amino acid combines with the amino group of another amino acid we get only one dipeptide as only one –$COOH$ group and one –$N{H}_2$ group is available.

D) Protein is a polypeptide with more than hundred amino acid residues (Molar mass > 10,000).