Question

Write the complete structures for the following peptides. Tell whether each peptide is acidic, basic, or neutral.

1. Methionylthreonine
2. Threonylmethionine
3. Arginylaspartyllysine
4. Glu-Cys-Gln

Short answer

The structures of the peptides have been drawn and nature of each peptide has been stated:

Step-by-step solution

Step-1. Explanation of part (a):

A peptide can be defined as the short chain of amino acids. The amino acids in a peptide are connected to one another in a sequence by bonds called peptide bonds.Peptides acts as structural components of cells and tissues, hormones, toxins, and enzymes. Examples of peptides includes the hormone oxytocin, glutathione, glucagon etc.

In part (a), peptide is neutral in nature as there are no acidic or basic side chains present.

Step-2. Explanation of part (b):

A peptide can be defined as the short chain of amino acids. The amino acids in a peptide are connected to one another in a sequence by bonds called peptide bonds.Peptides acts as structural components of cells and tissues, hormones, toxins, and enzymes. Examples of peptides includes the hormone oxytocin, glutathione, glucagon etc.

In part (b), peptide is neutral in nature as there are no acidic or basic side chains present.

Step-3. Explanation of part (c):

A peptide can be defined as the short chain of amino acids. The amino acids in a peptide are connected to one another in a sequence by bonds called peptide bonds.Peptides acts as structural components of cells and tissues, hormones, toxins, and enzymes. Examples of peptides includes the hormone oxytocin, glutathione, glucagon etc.

In part (c), peptide is basic in nature as the structure has two basic side chains and one acidic side chain.

Step-4. Explanation of part (d):

A peptide can be defined as the short chain of amino acids. The amino acids in a peptide are connected to one another in a sequence by bonds called peptide bonds.Peptides acts as structural components of cells and tissues, hormones, toxins, and enzymes. Examples of peptides includes the hormone oxytocin, glutathione, glucagon etc.

In part (d), peptide is acidic in nature as the structure has carboxylic acid side chain and weakly acidic thiol group.