Chapter 14.6, Problem 14.16CE

(a)

Interpretation Introduction

Interpretation:

For the given Glycine molecule structural formula has to be written for its zwitterion form.

Concept Introduction:

• Many amino acids are linked together through amide bonds to form a biologically large molecule known to be proteins.
• Amino functional group is $(-N{H}_2)$ and carboxyl functional group is $(-COOH)$ and a $R$(alkyl) group is considered as side chain, all these are bonded to same carbon atom.
• Zwitterion has both positive as well as negative charge, it is also called neutral dipolar ion.
• Zwitterion accepts proton in acidic condition and in basic condition zwitterion lose its proton.
• At low $pH$, amine and carboxylic acid are protonated and at high $pH$ amine and carboxylic acid are deprotonated.

(b)

Interpretation Introduction

Interpretation:

Structural formula of glycine molecule at low $pH$ of 2 and at high $pH$ of 10 has to be drawn.

Concept Introduction:

• Many amino acids are linked together through amide bonds to form a biologically large molecule known to be proteins.
• Amino functional group is $(-N{H}_2)$ and carboxyl functional group is $(-COOH)$ and a $R$ group is considered as side chain, all these are bonded to same carbon atom.
• Zwitterion has both positive as well as negative charge, thus it is also called neutral dipolar ion.
• Zwitterion accepts proton in acidic condition and in basic condition zwitterion lose electrons.

At low $pH$, amine and carboxylic acid are protonated and at high $pH$ amine and carboxylic acid are deprotonated