A polymer, P, can be made from the monomers benzene-1,4-dioyl chloride and benzene-1,3-diamine. Benzene-1,4-dioyl chloride has structure with a benzene ring, two -COCl groups attached at positions 1 and 4. Benzene-1,3-diamine has structure with a benzene ring, two -NH2 groups attached at positions 1 and 3.

1. (a)(i)Draw a section of the polymer chain of P. Your structure should include two repeat units. P[2]
2. (a)(ii)Place one tick in the table to describe polymer P and its method of polymerisation. type of polymer | type of polymerisation | addition | condensation polyalkene polyamide polyester[1]
3. (a)(iii)State whether or not polymer P is biodegradable. Give a reason for your answer.[1]
4. (a)(iv)State a suitable reagent to produce benzene-1,4-dioyl chloride from benzene-1,4-dicarboxylic acid.[1]
5. (a)(v)Benzene-1,3-diamine can be made from benzene using the reaction sequence shown. Step 1: Benzene to O₂N-C₆H₄-NO₂. Step 2: O₂N-C₆H₄-NO₂ to O₂N-C₆H₄-NH₂. Step 3: O₂N-C₆H₄-NH₂ to H₂N-C₆H₄-NH₂. State the reagents used for steps 1 and 3. step 1 step 3[2]
6. (b)(i)Describe what is meant by each of these terms. primary structure secondary structure tertiary structure[3]
7. (b)(ii)Name the forces or bonds responsible for holding together the primary structure of a protein molecule.[1]
8. (b)(iii)Name the forces or bonds responsible for the stabilisation of the secondary structure of a protein molecule, and identify the groups of atoms within the protein molecule that are held together by these forces or bonds.[2]

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