Protein1. (a)(Linear) sequence / order / arrangement / pattern of amino acids;2(b)Description of H bond / attraction between dipoles e.g + and /weak electrostatic bondBetween H and O;In amine and carboxyl groupsReference to the helix / secondary structure / - sheet/ strand ;(Bond between) R groups in coiling / tertiary stucture / 3D shapeMax 3(c)Long chain / long strand / fibrils / reference to linear moleculeRepeating sequence of amino acids;Many parallel strands lie side by side /eq;Reference to a helix / (pleated) sheet;Collagen has triple helix;Max 3[8]

2. Award marking points only in correct context1Consists of amino acids held together by peptide bonds (in either) ;2Insulin is globular and collagen is fibrous ;3Hydrogen bonds hold, secondary structure / (alpha) helix / beta strands, in shape (in either) ;4R groups determine, tertiary / 3D, shape (in either) ;5Reference to named type of bonding in tertiary structure ;Insulin6Relatively small protein / 51 amino acids ;7Reference to, alpha helix / beta sheet ;8Two polypeptide chains / A chain and B chain ;9Reference to disulphide bonds ;10Reference to binding site for cell membrane receptor ;Collagen11Relatively large protein / over 1000 amino acids ;123 polypeptide chains / triple helix ; [ignore alpha here]13Hydrogen bonds between chains ;14Regular amino acid sequence / repeating sequence ;15Molecules form (micro)fibres / cross-linking between molecules ;[10]3. amino acids / polypeptides / peptides ;peptide ; [not dipeptide] [accept peptide / hydrogen / disulphide / ionic if peptide or polypeptides given above]condensation / polymerisation ;() helix / (alpha) helix ;hydrogen / H ;

4. (a)Folding of secondary structure / eq ;To form irregular / 3D / globular shape ;Maintained by, hydrogen / ionic / disulphide bonds / eq ;Bonding determined by R-groups ;Shape is important for function ;max 3