All India Engineering / Architecture Entrance Examination (AIEEE)

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AIEEE 2007 Chemistry

Q. 8. The secondary structure of protein refers to:

1. helical backbone.
2. hydrophobic interactions.
3. sequence of amino acids.
4. fixed configuration of the polypeptide backbone.

Sol: Secondary structure of a protein refers to the fixed configuration of the polypeptide skeleton. helix structure results only when intramolecular H−bonds are formed between of one amino acid residue and N−H of fourth amino acid residue in polypeptide chain. pleated structure is formed when intermolecular H−bond is formed between of one polypeptide chain with N−H of the other chain. Correct choice: (4)

Q. 9. Which of the following reactions will yield 2,2−dibromopropane?

Sol:

Correct choice: (1)

Q. 10. In the chemical reaction, the compounds (A) and (B) are respectively:

Sol: This is carbylamine reaction. Correct choice: (4)

Q. 11. The reaction of toluene with Cl₂ in presence of FeCl₃ gives predominantly:

1. benzoyl chloride
2. benzyl chloride
3. o− and p−chlorotoluene
4. m−chlorotoluene

Sol:

The reaction proceeds by electrophilic substitution mechanism.
Correct choice: (3 )