1. (a) What is the meaning of the term ‘chiral molecules’ Chiral molecules are two forms of a molecule which are mirror images of each other and cannot superimpose with each other. These molecules usually consist of an asymmetric centre (chiral centre).

2. (b) Give the IUPAC name for ‘alanine’. 2-aminopropanoic acid

3. (c) Explain why the alanine found in organisms contains only one form of the chiral molecule while the product from hydrogenation reaction of 2-aminopropenoic acid by using nickel or platinum as catalyst contains both of the two forms of the chiral molecules of alanine in equal amount. Explain your answer. Substance synthesis from organism usually catalyse by enzymes and hence the molecules are locked by the enzyme molecule with specific orientation.

4. (d)State the method used to distinguish whether an unknown substance whether it consists of one form of chiral molecule or both two forms of chiral molecules in equal amount. We may use a polarimeter to detect the unknown substance. Substance consists of only one form of chiral molecule can rotate the polarized light while those cannot rotate the polarized light would consist of two forms in equal amount.

5. (e) Give two reasons why the Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry for those Laureates in 2001. They develop the catalytic asymmetric synthesis of one form of pure optically active isomer. The processes are very useful in manufacture of pharmaceutical drugs.