Question

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For - C - N H (peptide bond)
(a) C — N bond length in proteins is longer than usual
bond length of the C — N bond
(b) Spectroscopic analysis shows planar structure of the
— C —NH— group
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(c) C — N bond length in proteins is smaller than usual
bond length of the C—N bond
(d) None of the above

Answer 1

Answer:

Due to the resonance effect in amino acid the CNCN bond length becomes shorter than single bonded C-NC−N bond length.

Answer 2

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For - C - N H (peptide bond) :

• Peptide bond is amide covalent linkage between two consecutive alpha-amino acid from carbon number one of alpha-amio acid and nitrogen number two of other alpha-amino acid.

• Also known as eupeptide bond.

• First alpha amino acid loses hydrogen and oxygen from -COOh, other loses hydrogen from -NH2. Gives water as by-product.

• Due to its resonance stabilization, it do not react under normal conditions.

• Also due to its resonance stabilization, C — N bond length in proteins is smaller than usual

bond length of the C—N bond.