Define quaternary structure in proteins.

Outline the importance of polar and non-polar amino acids in proteins.

Describe non-competitive inhibition.

the linking together of two or more polypeptides to form a protein

polar and non-polar amino acids help determine protein structure;
polar amino acids on the outside of proteins make them soluble in water;
polar amino acids in channels in membranes allow passage of polar substances/ reference to surface proteins or membranes;
polarity or non-polarity of surface amino acids on proteins determines their interaction with other molecules (substrates, hormones, signalling molecules);

inhibitor molecule attaches to enzyme at site away from active site/attaches to allosteric site;
binding of inhibitor molecule alters shape of active site/causes conformational change;
shape change in active site disables enzyme from accepting substrate/reduces enzyme activity/destroys enzyme functionality;
increasing substrate concentration has no effect on the inhibitor;
irreversible;

Most answers were correct.

Very few candidates were able to outline the importance of polar and non-polar amino acids in proteins.

In general candidates did know how noncompetitive inhibitors work.