Question

Glycine and Alanine are different with respect to one substituent on the α-carbon. What are the other common substituent groups?

Answer 1

The R-group in these proteinaceous amino acids could be hydrogen (the amino acid is called glycine), a methyl group (alanine), hydroxy methyl (serine), etc.

\[\begin{array}{cc}
\phantom{...}\ce{COOH}\\
|\phantom{...}\\
\ce{H - C - NH2}\\
|\phantom{...}\\
\ce{\underset{Glycine}{H}}\phantom{...}
\end{array}\]

 

\[\begin{array}{cc}
\phantom{...}\ce{COOH}\\
|\phantom{...}\\
\ce{H - C - NH2}\\
|\phantom{...}\\
\ce{\underset{Alanine}{CH3}}\phantom{...}
\end{array}\]

 

\[\begin{array}{cc}
\phantom{...}\ce{COOH}\\
|\phantom{...}\\
\ce{H - C - NH2}\\
|\phantom{...}\\
\phantom{......}\ce{\underset{Serine}{CH2 - OH}}
\end{array}\]

Amino acids