Predicting the Type of Polymerisation (CIE A Level Chemistry)

The structure of dehydroalanine, shown in Fig. 2.1, makes it an unusual amino acid.

Fig. 2.1

Name the functional group, in dehydroalanine, that is not common to other amino acids.

Draw one repeat unit of the addition polymer formed by dehydroalanine.

Dehydroalanine does not easily form a condensation polymer because of the alkene functional group.

The addition of hydrogen to dehydroalanine produces alanine, CH₃CH(NH₂)COOH. Alanine is easily able to form a condensation polymer.

Draw two repeat units of the condensation polymer formed by alanine. The new functional group formed should be displayed. 

Glycine and serine are amino acids with the systematic names 2-aminoethanoic acid and 2-amino-3-hydroxypropanoic acid respectively.

Draw the structures of glycine and serine.

Serine exists as a pair of optical isomers. The structure of one optical isomer is shown in Fig. 3.2.

Fig. 3.2

Draw the three-dimensional structure of the other optical isomer of serine.

Glycine and serine can react to form condensation polymers that contain ester and amide functional groups.

Identify the correct pairings that will separately form an ester and amide.