Question

What is the predominant form of each of the following amino acids at pH=11? What is the overall charge on the amino acid? (a)valine; (b)proline; (c)glutamic acid; (d)lysine?

Short answer

Amino acids constitute an important biomolecule that is vital to execute several functions. The deficiency of these molecules can lead to disorders like insomnia, hypoglycemia, etc.

Step-by-step solution

Amino acid

Amino acids constitute an important biomolecule that is vital to execute several functions. The deficiency of these molecules can lead to disorders like insomnia, hypoglycemia, etc.

Amino acids and pH values

When pH value is larger than pI, several hydroxide ions are in the solution.These negatively charged ions come near to the positively charged ions leading to the hydrogen ion removal.

This makes the amino acidshave an overall negative charge.

Predominant form of various amino acids at pH=11

(a)The amino acid valine comprises one amino group and one carboxylic acid. The overall charge of the compound is -1 at pH=11. The structure can be given as:

Structure of valine at pH=11

(b)The amino acid proline comprises one amino group and one carboxylic acid group. The overall charge of the compound is -1 at pH=11. The structure of proline at pH=11

can be given as:

Structure of proline at pH=11

(c)The amino acid glutamic acid comprises one amino group and two carboxylic acid groups. The overall charge of the compound is -2 at pH=11. The structure of the compound at pH=11 can be given as:

Structure of glutamic acid at pH=11

(d)The amino acid lysine comprises of two amino groups and one carboxylic acid group. The overall charge of the compound is -1 at pH=11. The structure of lysine at pH=11 can be given as:

Structure of lysine at pH=11