Final answer:
Inhibitors that bind to receptor proteins and inhibit a response can function through allosteric inhibition, changing the enzyme's conformation and efficiency. The binding of ligands to receptors is influenced by an equilibrium constant that determines the likelihood of a receptor being occupied. Tyrosine kinase receptors are an example of how receptor-ligand binding can initiate and terminate cellular responses.
Step-by-step explanation:
The substances that bind to receptor site proteins and then inhibit a response are known as inhibitors. These inhibitors can function by binding to the active site of an enzyme, or to a separate, allosteric site, inducing a conformational change that reduces the enzyme's ability to bind to its substrate effectively. For example, some inhibitor molecules bind to enzymes in a location where their binding induces a conformational change that reduces the affinity of the enzyme for its substrate, termed allosteric inhibition. Cell-surface receptors and internal receptors handle binding differently. While cell-surface receptors bind to hydrophilic ligands and may initiate signaling pathways indirectly, internal receptors bind to hydrophobic ligands and can directly influence transcription and translation.
Receptor-ligand systems are influenced by the equilibrium constant, k, which dictates the distribution between receptor-bound and unbound ligands. A high k value indicates that a receptor is likely to be occupied, which is necessary for ligand dissociation in order to initiate a new stimulus response cycle. Conversely, tyrosine kinase receptors activate cellular responses when ligands like insulin bind to them, with the signal being switched off once the ligand dissociates.