Ever wonder how a human body controls all the cells simultaneously and carries out day-to-day functions. Maybe a cell does all the work required, but what controls the suitable cell to activate at the right time? The hormones and enzymes regulate, control, and catalyze almost all bodily functions. Although enzymes and hormones are involved in various cellular activities, they have many differences.
The significant difference between enzymes and hormones is their role in the body. Enzymes are the biological or organic catalysts known for enhancing the rate of biochemical reactions but not interacting with the substances involved.
In contrast, hormones are biological molecules produced by the endocrine gland that control almost all the physiological and metabolic responses of the body.
Enzymes are specific as an enzyme works for one particular reaction/substrate or group of similar substrates. For example, “glucose oxidase” is an enzyme that catalyzes reactions involving D-glucose only but none of the other monosaccharides. The hormones are less specific and are produced far from the target cell or organs and carried by the blood to the target cell. Growth hormone (GH) is produced by the pituitary gland and plays a role in the growth of different body parts.
Substrates are chemical substances that are modified by enzymes.
The Difference Between Enzymes and Hormones
Although enzymes and hormones are found inside, these have vast differences in their functions, secreting cells/tissues, weight, circulation, and many more. The detailed difference is as follows:
| Properties | Enzymes | Hormones |
| Definition | Enzymes are biocatalysts that increase the reaction rate. | Hormones are biological components that control almost all bodily functions. |
| Secreting cells/tissues/glands | Enzymes are secreted by exocrine glands like the salivary gland and cells of the stomach, intestine, liver, and pancreas. | Endocrine glands like the pituitary, thymus, thyroid, pancreas, and adrenal glands secrete hormones. |
| Composition | The enzymes are amino acids linked with one or two polypeptide bonds. | The hormones are derived from amino acids or lipids. The protein and peptide hormones are derivatives of tryptophan and serine. Steroids are derivatives of cholesterol (lipid). |
| Structure | Amino acids in the chain form the primary structure.The folding of the primary structure in the alpha helix or beta sheet is the secondary structure. The arrangement of amino acids in the 3D is the tertiary structure. | Peptide hormones are in a chain of amino acids.Steroid hormones comprise 17 carbon atoms fused in four rings (three cyclohexane rings and one cyclopentane ring). |
| Weight | The molecular weight of enzymes ranges from 10,000-20,00,000 dalton (Da). | Hormones have molecular weight of less than 4000 Da. |
| Types | There are six types of enzymes; hydrolases, oxidoreductases, transferases, ligases, isomerases, and lyases. | Based on their chemical nature, hormones are of 3 kinds; amino acid derivatives, peptide hormones, and lipid derivatives (steroids). Based on their area of action, hormones are of two types; local and general. |
| Circulation System | Enzymes are produced near the target cell or the target cell itself, so circulation is intracellular or some ducts. | Hormones are circulated with the help of blood. |
| Function | Increasing the rate of any biochemical reaction. | Signal carrier from a cell to another cell or an organ to another organ. |
| Dependency | Enzymes rely on the signals from hormones. | Hormones do not rely on enzymes. |
| Type of reaction | Reversible | Irreversible |
| Recyclable | Enzymes are recyclable. | Hormones are not recyclable. |
| Time required for response | The time taken for action by enzymes is fast. | Some hormones take a longer time to act, but some are quick. |
| Concentration | Decrease in the concentration halts the reaction, whereas the increase in concentration speeds the reaction. | An increase and decrease in concentration lead to different disorders. |
| Diseases associated | Deficiency of the enzyme cause life-threatening diseases, like Nieman-Pick disease, lysosomal storage disorders, etc. | Hormone imbalance (decrease and increase) leads to many diseases like Hashimoto’s disease, Grave’s disease, etc. |
| Examples | The examples of enzymes are amylase, lipase, trypsin, maltase, etc. | Some examples of hormones are estrogen, progesterone, LH (luteinizing hormones), growth hormones (GH), cortisol, etc. |
Hashimoto’s disease is an autoimmune disorder where the thyroid secretes less thyroid hormone (hypothyroidism).
Grave’s disease is an autoimmune disorder in which overproduction of thyroid hormone occurs.
Nieman-Pick disease is a rare condition in which the body has difficulty metabolizing fats (lipids and cholesterol) within cells.
Lysosomal storage disorder is an inherited metabolic disease due to abnormal build-up of toxic materials in cells because of enzyme deficiencies.
Types of Enzymes
The enzymes are named with the suffix -ase after the reaction they catalyze. The enzymes are categorized into different types based on the reaction they catalyze. The enzyme classification with the reaction type is as follows:
| Enzyme | Reaction Type | Example |
| Oxidoreductases | Oxidation/Reduction | Pyruvate dehydrogenase; oxidation of pyruvate to acetyl CoA, alcohol dehydrogenase, glucose oxidase, etc. |
| Transferases | Transfer of atom or group of atom | Transaminase; transfers amino group |
| Lyases | Group removal | Aldolase, decarboxylase, |
| Ligases | Joining of molecules by phosphodiester bond | DNA ligase; join two DNA molecules |
| Isomerases | Isomerization | Triose phosphate isomerase, biphosphoglycerate mutase, photoisomerase, etc. |
| Hydrolases | Hydrolysis | Lipase, pepsin, |
Types of Hormones
Hormones are classified based on their chemical nature and action area.
Based on Chemical Nature
| Hormones | Chemical Nature | Examples |
| Amine derivatives | Derivatives of the amino acids tryptophan and tyrosine | Dopamine, epinephrine, norepinephrine, etc. |
| Peptides | Long chain of aminoacids | Oxytocin, Insulin, etc. |
| Lipid or cholesterol derivatives | Derivates of the lipid cholesterol | Cortisol, testosterone, estrogen, etc. |
Based on Action Area
| Hormones | Action Area | Examples |
| Local hormones | The signaling action area is localized to a single organ or system. | Acetylcholine, secretin, cholecystokinin, etc. |
| General hormones | The signaling action area is general or many different cells and specific cells. | Growth hormone works on all the cells, whereas adrenocorticotropin stimulates the adrenal cortex. |
Reference
- Biochemistry of Hormones. Biochem.zsmu.zp.ua. (2015). Retrieved 21 July 2022, from https://biochem.zsmu.zp.ua/wp-content/uploads/2017/04/Biochemistry-of-hormones.pdf.
- Robinson, P. (2015). Enzymes: principles and biotechnological applications. Essays In Biochemistry, 59, 1-41. https://doi.org/10.1042/bse0590001
- Blanco, A., & Blanco, G. (2017). Enzymes. Medical Biochemistry, 153-175. https://doi.org/10.1016/b978-0-12-803550-4.00008-2
- e.hormone | Endocrine System: Types of Hormones. E.hormone.tulane.edu. Retrieved 21 July 2022, from http://e.hormone.tulane.edu/learning/types-of-hormones.html.
- Biga, L., Dawson, S., Harwell, A., Hopkins, R., Kaufmann, J., & LeMaster, M. et al. 17.2 Hormones. Open. Oregon state. education. Retrieved 21 July 2022, from https://open.oregonstate.education/aandp/chapter/17-2-hormones/.
- Nelson, D., Lehninger, A., Cox, M., & Nelson, D. (2005). Lecture notebook for Lehninger principles of biochemistry, fourth edition (4th ed.). W.H. Freeman.
