Are enzymes substrate-specific and only bind to one substrate?

Answer 1

Hi Vanessa R.,

Enzymes are variously specific. In nature, they tend to act on their target substrates, but the mechanism of action of many drugs is binding to a target enzyme and disabling it. In some cases this binding site is the one used by the natural substrate, but it doesn't have to be; the drug may bind to a different place on the enzyme and alter the enzyme shape a little so as to prevent it from binding and acting on its natural substrate.

The binding of molecules is a fascinating field in itself, you may wish to look up "allosteric activator" and "allosteric inhibitor". Your body makes use of this (allosteric activator effect) in hemoglobin, which loads in oxygen to its 4 sites (it has a quaternary structure) in an all-or-none manner, which considerably increases your red blood cells' oxygen uptake and release process completeness.

-- Cheers, -- Mr. d.