DIFFERENCE BETWEEN RECEPTORS AND ENZYMES

What is the difference and similarities between receptors and enzymes?

Like enzymes, receptors are common targets in drug discovery. Receptors act as switches that can be turned on or off. When turned on, receptors initiate a cascade of events that ultimately produce a biological response.

The body contains thousands of different receptors. Despite their diversity, almost all receptors can be classified into a handful of different receptor superfamilies.

Receptors bind molecules that either activate or suppress the normal function of the receptor. The impact of receptor binding can be modeled mathematically to allow better understanding of receptor function. Better understanding of receptor function ultimately allows for the design of safer, more effective drugs.

Both enzymes and receptors are proteins, and therefore both biological structures share many fundamental similarities. Regardless their roles within a biological system are distinct from one another.

Similarities
As proteins, both enzymes and receptors possess the same aspects of primary, secondary, tertiary, and quaternary structure. Just as with enzymes, proper folding of a receptor depends on environmental factors, including temperature and pH. The shape of a receptor is crucial because, like enzymes, receptors operate by binding other molecules, called ligands.

The similarities between enzymes and receptors allow both systems to be modeled with many of the same mathematical equations. Most treatments of receptors and enzymes appear to be very different, but the derivations and theories can largely be recycled between the two.

Difference
The primary difference between receptors and enzymes lies in what they do. Enzymes convert a substrate to a product. Receptors do not catalyze a reaction or otherwise convert a ligand. Instead, receptors bind a ligand, or primary messenger.

Upon binding a ligand, a receptor changes its conformation to initiate a series of events. These events may involve a number of other agents, including enzymes (effectors), binding proteins (transducers), and/or other signaling molecules (secondary messengers).

The number of other players in the pathway depends on the particular receptor. Each ligand can potentially produce many secondary messengers, a phenomenon known as signal amplification. Ultimately, the entire process generates an observable biological response.