Differences among enzymes, hormones and vitamins-
Indeed, earlier, the distinction between vitamins and hormones was no longer believed to be tenable. But there exists a fundamental difference between these two classes of active substances: the hormones are regulatory substances where as the vitamins are accessory nutrients.
The vitamins also differ from the hormones in that they are supplied to the body from some external source (i.e., chiefly from the food ingested) where as the hormones are synthesized within some part of the body of an organism.
Moreover, most vitamins and some hormones are involved either directly or indirectly in enzyme systems in order to carry out biochemical functions.
Some vitamins are also known to be coenzymes.
Enzymes- these are proteinaceous specific catalytic substances which are synthesized by the animal cells. Unlike vitamins they are not consumed or taken orally during growth phase. Basically they aid in initiating and continuing the biological reactions and hence operates the biological systems.
Examples- Lipase, Urease, Trypsin, Pepsin, chromosome oxidase etc.
Hormones- These are steroids, peptides or amino acid derivatives which mainly perform the regulatory functions. They are synthesized in some specific parts of the body and are secreted into the bloodstream directly without being collected into ducts. They are consumed during growth. only some hormones are involved in enzyme system.
Examples - insulin, adrenaline, thyroxine relaxin, testestrone, intermediate, etc.
Vitamins- these are accessory nutrients which belong to diverse group chemically. These are not synthesized by most animal cells but supplied to the body from outside sources (like plant and bacterial world). the influence the rate of reactions at which they proceed. They are consumed during growth. Most of them are involved in enzyme systems.
Example - calciferol, thiamin, niacin, pantothenic acid, etc.