It is often an enzyme that converts an inactive precursor molecule into an active second messenger.
A class of(usually small) molecules that regulates the activity of a specific protein (e.g., enzyme) molecule by binding to a specific site on the protein. Control of (existing) enzyme molecules may be achieved by combination of the effector with the enzyme. The effector molecule may either physically block the active site on the enzyme molecule, or alter the threedimensional conformation of the enzyme molecule. That conformation change results in a change in the enzyme’s catalytic activity. Effector is a general term. Effector molecules may be activators (cause an increase in the enzyme’s catalytic activity) or inhibitors (cause a decrease in the enzyme’s catalytic activity). A special class of effector, known as an allosteric effector, binds to enzyme molecule at a site other than the enzyme’s active site (thereby activating or inhibiting).
A muscle or gland that carries out responses to nervous stimuli or impulses.
A nerve ending in muscles or glands which is activated to produce contraction or secretion.
Organ that becomes active in response to stimulation; nerve fiber that terminates on a muscle or gland and stimulates contraction.
Any structure or agent that brings about activity in a muscle or gland, such as a motor nerve that causes muscular contraction or glandular secretion. The term is also used for the muscle or gland itself.
A cell, tissue, or organ that produces the final result of a stimulus.