S.N. |
Hormones |
Enzymes |
1. |
Hormones may be amino acid derivatives, peptides, proteins or steroids in nature. |
All enzymes are complex proteins. |
2. |
They have low molecular weight. |
They have high molecular weight. |
3. |
They often readily diffuse through cell membranes. |
They are not diffusible. |
4. |
They are secreted by cells in endocrine glands at one site and are carried by blood to the target site. |
They are secreted by cells in exocrine glands and may act in the cells themselves or pass via ducts to act in their target site. |
5. |
They are often used up in their regulatory action. |
They remain unaffected in the reaction they catalyze. |
6. |
Hormone-controlled actions are not reversible. |
Enzyme-controlled reactions are reversible. |
7. |
Hormones either accelerate or reduce the rate of specific physiological process. |
They normally speed up the biochemical reactions. |
8. |
They are effective in low concentrations. |
They also act in low concentrations, but the rate of enzyme-catalyzed reactions steadily increases with an increase in their concentration. |
9. |
They may act either slowly or quickly. |
They act quickly. |