271.
Which of the following represents a peptide chain?
A
\[-NH\underset{\begin{smallmatrix}
\parallel \\
O
\end{smallmatrix}}{\mathop{-C-}}\,NH\underset{|}{\overset{|}{\mathop{-C-}}}\,NH\underset{\begin{smallmatrix}
\parallel \\
O
\end{smallmatrix}}{\mathop{-C-}}\,NH-\]
B
\[-NH\underset{\begin{smallmatrix}
\parallel \\
O
\end{smallmatrix}}{\mathop{-C-}}\,C{{H}_{2}}-C{{H}_{2}}C{{H}_{2}}-NH-C{{H}_{2}}C{{H}_{2}}\underset{\begin{smallmatrix}
\parallel \\
O
\end{smallmatrix}}{\mathop{-C-}}\,\]
C
\[-NH-C{{H}_{2}}\underset{\begin{smallmatrix}
\parallel \\
O
\end{smallmatrix}}{\mathop{-C-}}\,NH-C{{H}_{2}}\underset{\begin{smallmatrix}
\parallel \\
O
\end{smallmatrix}}{\mathop{-C-}}\,NH-C{{H}_{2}}-\]
D
\[-NH-C{{H}_{2}}C{{H}_{2}}\underset{\begin{smallmatrix}
\parallel \\
O
\end{smallmatrix}}{\mathop{-C-}}\,NH-NH-C{{H}_{2}}\underset{\begin{smallmatrix}
\parallel \\
O
\end{smallmatrix}}{\mathop{-C-}}\,C{{H}_{2}}-\]
Answer :
\[-NH-C{{H}_{2}}\underset{\begin{smallmatrix}
\parallel \\
O
\end{smallmatrix}}{\mathop{-C-}}\,NH-C{{H}_{2}}\underset{\begin{smallmatrix}
\parallel \\
O
\end{smallmatrix}}{\mathop{-C-}}\,NH-C{{H}_{2}}-\]
$$D$$ - glucose exists in two optically active forms known as $$\alpha {\text{ - D - }}$$ glucose and $$\beta {\text{ - D - }}$$ glucose. The two isomers are interconvertible in aqueous solution.
Carbon-1 in both configurations I and II is called an anomeric carbon atom.