(i) enzymes are biocatalysts that help the reactions in the bodies of living things to proceed under relatively mild conditions. Enzymes are generally globular proteins. An example of an enzyme is maltase, which helps catalyze the hydrolysis of maltose into glucose.
(ii) vitamins are organic chemical compounds that are necessary for humans since their lack would lead to deficiency diseases. Most of the vitamins are not synthesized by the human body but are obtained from other sources, such as plants. Examples – Vitamin B1 (or thiamine), Vitamin C (or Ascorbic acid).