Are Hormones Enzymes? The Similarities And Differences

Hormones and enzymes are two proteins that are commonly mistaken for each other. I will say this is because they are proteins and tend to sound similar. Also, some hormones and enzymes are produced by the same organ.

For instance, the pancreas, which is made of the endocrine and exocrine glands, secretes and produces these biomolecules. The endocrine glands produce hormones that act as chemical messengers, and the exocrine glands produce enzymes that enhance the rate of certain biological processes.

You can see that both biomolecules are proteins, but they have their differences. Continue reading to explore the differences between these two essential proteins.

What are hormones?

Hormones are chemical-signalling molecules with the primary function of sending messages to target glands and organs. They are proteins, amino acids, or amines that are released into the bloodstream to circulate messages to different specific organs.

Hormones regulate physiological processes like digestion, sleep, respiration, growth, development, metabolism, reproduction, etc. You can call hormones initiators of biological processes.

Hormones can be classified as either protein or steroid hormones. Protein hormones react with the receptors on the surface of the cell and the resulting hormonal action is rapid.

On the other hand, steroid hormones react with the receptor sites in the cell and the sequence of events is slower. Steroid hormones are usually involved in protein synthesis.

What are enzymes?

Enzymes are biocatalysts. They are complex or conjugated proteins with a three-dimensional structure that help to regulate biological processes in living organisms. They speed up metabolic processes in cells, wine fermentation, cheese curdling, and beer brewing.

Enzymes have an active site to which the substrate binds. The active sites make enzymes specific for substrates and their actions. In addition, enzymes could either be catabolic or anabolic.

Catabolic enzymes are enzymes that break down their substrates while anabolic enzymes are enzymes that build complex molecules from their substrates.

Are hormones enzymes?

No, hormones are not enzymes. Although both substances are proteins, they are different from each other. Hormones are signaling biomolecules, while enzymes are biocatalysts.

Similarities between hormones and enzymes

  • They are both proteins
  • Both substances are produced by the body; they are not obtained from food
  • Both are necessary for the proper running of physiological processes
  • Both biomolecules are specific in action
  • The functions of enzymes and hormones are determined by their shapes
  • Hormones and enzymes are soluble and diffusible
  • In addition, both are needed in minute quantities

Differences between hormones and enzymes


Both are proteins but not all hormones are proteins. Except for the sex hormones and hormones of the adrenal cortex, all other hormones are proteins.

Hormones are steroids or peptides released by a part of a living organism. They send messages to other organs or tissues to initiate cellular reactions.

Enzymes are proteins that speed up biochemical reactions but are not changed in the process. However, hormones are changed during the reaction.

Hormones are chemical messengers that are formed in the endocrine glands and enzymes are biological catalysts that are formed in the exocrine glands.

Hormones are diffusible and the type of hormones present in a living organism change with age. Some hormones disappear and new ones appear with age. In contrast, enzymes are nondiffusible and do not change with age.

Additionally, enzymes have vitamins and inorganic elements as prosthetic groups which are responsible for their reactions. Hormones do not have such groups.

Molecular weight

Enzymes are macromolecules with large molecular weight, while hormones have a low molecular weight in comparison to enzymes.


While hormones react at the target organ, enzymes react at the site of production. Enzymatic action is quick and reversible but hormonal action is irreversible and could be quick or slow, depending on the type of hormone. Also, are reusable but hormones are not.

Some hormones rely on other hormones to initiate action, but enzymes are more independent. They do not rely on each other for activation. Both substances are needed in minute quantities, but enzymes are needed in more amounts than hormones.

For enzymes, the rate of the reaction varies with enzyme concentration. The more the enzyme, the faster the reaction. On the other hand, an excess or a deficiency of hormones leads to disease.

Furthermore, enzymatic action is intracellular and may occur in some ducts. Hormonal action always takes place in the bloodstream.


Going further into their functions, enzymes are involved in digestion while hormones are involved in metabolic processes, such as the growth and development of organs and tissues, sexual development and reproduction, regulation of available heat and energy, and regulation of the internal balance between the concentration of water and ions.

The overall function of an enzyme is dependent on the presence of a substrate, while the function of a hormone depends on positive and negative feedback mechanisms.

 In biological reactions, enzymes act as catalysts, speeding up the rate of biological processes. On the other hand, hormones send messages to organs or tissues. Hormones regulate morphogenesis but enzymes do not.

Hormones have diverse functions. They help to control and regulate body growth and overall physiology, whereas enzymes are limited in their functions.

Regulation and inhibition

Enzymes are regulated by temperature, pH, allosteric control, protein turnover, covalent modification, isoenzymes, and proteolytic activation. Hormones are regulated by the brain and other external factors.

Enzyme inhibition is usually caused by specific inhibitor molecules, whereas hormonal inhibition is caused by inhibitor hormones.


Examples of enzymes include lipase, oxidases, isomerase, hydrolases, trypsin, amylase, maltase, lactase, etc. These enzymes are produced in cells of the salivary glands, stomach, pancreas, and glands in the small intestine.

Examples of hormones include testosterone, estrogen, cortisol, oxytocin, progesterone, insulin, glucagon, growth hormone, etc. Any of these hormones are produced in cells of the pancreas, adrenal glands, pituitary gland, thymus gland, and thyroid gland.

How do hormones and enzymes work together?

Hormones can influence enzyme activity by stimulating protein synthesis and gene expression. They are responsible for the secretion of digestive enzymes in the stomach and intestine in the process of digestion and absorption.

Also, hormones initiate biological processes, and enzymes take it from there, acting as catalysts that speed up the rate of the reactions. That is, enzymes depend on the messages from hormones, but hormones do not depend on enzymes.


Are all proteins hormones and enzymes?

Not all proteins are hormones and enzymes. All enzymes and hormones are proteins. However, some hormones may be made of amino acids or amines.

Can enzymes affect pH?

No. Enzyme activity is altered by changes in pH, not the other way around. Every enzyme has its optimum pH range. When this value changes, it disrupts enzyme activity. The reaction could become slower, or the enzyme could become denatured.

What temperature denatures enzymes?

Enzymes begin to lose their catalytic activity at temperatures higher than 40°C. Enzymes naturally have a three-dimensional structure, and they vibrate when subjected to high temperatures.

As the temperature rises, the vibrations increase, and the enzymes shake out of their 3-D structure. Consequently, they become irreversibly denatured.

Are hormones destroyed by cooking?

Not all hormones are destroyed by the heat of cooking. Some hormones are partially denatured by cooking, some are fully denatured, and some aren’t affected in any way. For instance, the steroid hormones are heat resistant and are least affected by cooking.


All hormones and enzymes are proteins. However, not all proteins are hormones or enzymes. Hormones are released from endocrine glands and send messages to target glands and organs. They aid communication between tissues, thereby aiding several tissue functions.

On the other hand, enzymes are catalysts that break down large molecules into smaller and readily usable ones. They help to speed up physiological processes by attacking specific sites on the substrate. Also, the body needs more enzymes than hormones.

Learn about the effect of pH on enzyme activity.

Thanks for reading.