question_answer

Which statement is incorrect about peptide bond\[-\overset{\begin{smallmatrix}  O \\  |\,\,| \end{smallmatrix}}{\mathop{C}}\,-\overset{\centerdot \,\,\centerdot }{\mathop{NH}}\,-\]?                          [AIPMT 2001]

A) \[C-N\] bond length in proteins is longer than usual bond length of N-bond

B) Spectroscopic analysis show planar structure of \[-C-\underset{\begin{smallmatrix}  |\,\,\,| \\  O \end{smallmatrix}}{\mathop{NH}}\,-\] group

C) \[C-N\] bond length in proteins is smaller than usual bond length of \[C-N\] bond

D) None of the above

Correct Answer: A

Solution :

[a] Peptide bond is formed by the reaction of  group of one amino add with the  group of another amino acid and represented as

As partial double bond character found between  bond, the bond length of  in protein should be smaller than usual  bond.