(a) State four characteristics of enzymes

(b) (i) List two digestive enzymes produced in the duodenum of humans

(ii) Name the substrate that each enzyme listed in 2(b)(i) acts on.

(iii) State the products of each enzyme activity in 2(b)(ii)

(c) (i) State one way in which chlorophyll is important in plants

(ii) Name two macroelements that are required for the formation of chlorophyll in plants.

(iii) State one deficiency symptom of each macroelement named in 2 (c) (ii) above

(d) Outline the proce-dure used for testing for starch in a leaf