Question

What is the structure of each amino acid at its isoelectric point: (a) alanine (b) methionine; (c)aspartic acid; (d) lysine

Short answer

(a)

(b)

(c)

(d)

Step-by-step solution

Amino acid

Amino acids constitute primary importance as they carry out several functions. Numerous amino acids are present; however, the proteins are created from twenty amino acids.

Isoelectric point

The isoelectric point indicated as pI, impacts the solubility of a specific molecule at a particular pH. Proteins comprise a net positive charge at a pH less than pI. A net negative charge is present at a pH larger than pI.

Structure of each amino acid at the isoelectric point

The amino acid is found as a zwitterion at the isoelectric point. At the isoelectric point, the deprotonation of and the protonation of takes place.

(a)The structure of the amino acid, alanine at its isoelectric point can be given as:

Structure of alanine at the isoelectric point

(b)The structure of the amino acid, methionine at its isoelectric point can be given as:

Structure of methionine at the isoelectric point

(c)The structure of the amino acid, aspartic acid at its isoelectric point can be given as:

Structure of aspartic acid at the isoelectric point