PRACTICE MODUL SK025 2nd Edition

PRACTICE MODULE CHAPTER 12 SK025

9. An organic compound, Q has the following structural formula
O

HO C OH

CH2 CHNH2

It can be inferred that
I one mole of Q react with two moles of sodium hydroxide
II Q exist as a pair of optical isomers
III Q has a high melting point
Answer :

10. Given structure of alanine, an amino acid
COOH

H C NH2

CH3
Which of the following statement is true about alanine, pI = 6?
I Forms zwitterion
II Forms anion in a solution with pH>7
III Soluble in organic solvent
Answer :

WORKSHEET 12.6

MODEL OF PSPM QUESTIONS
1. Serine and alanine are examples of α-amino acid.

COOH COOH
CH3 C NH2
HOCH2 C NH2
H H
Ala
Ser

Give the IUPAC name of serine. Draw the structures of serine each in a strongly acidic and basic
medium. Draw the structures of all possible dipeptides when serine is reacted with alanine.

[5 marks]

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PRACTICE MODULE CHAPTER 12 SK025

O CH2OH O CH3
H2NCH C N CHCOOH
H2NCH C N CHCOOH
CH2OH H
CH3 H
Ser-Ala
Ala-Ser

2. The IUPAC name of alanine is 2-aminopropanoic acid. Two moles of alanine undergoes
condensation reaction to form dipeptide QQ. Alanine reacts with sodium nitrite in hydrochloric
acid at 0oC and left at room temperature to form RR, SS and TT. Draw the structure of QQ,
RR, SS and TT.
[4 marks]

Prepared by : Mdm Sharifah Fadthyah Bt Syed Baharuddin
Checked by : Mdm Noor Najihah bt Kamaruddin

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