Skip to Content


Pronunciation: e-fek'tor, -tor


  1. As defined by Sherrington, a peripheral tissue that receives nerve impulses and reacts by muscular contractioon, glandular secretion, or electric discharge (from an electric organ, as in the case of certain bony fishes such as the electric eel).
  2. A small metabolic molecule that, by combining with a repressor gene, depresses the activity of an operon.
  3. A small molecule that binds to a protein or other macromolecule and, in so doing, alters the activity of that macromolecule.
  4. An individual or a substance, technique, procedure, or person causing an effect.

[L. producer]

Disclaimer: This site is designed to offer information for general educational purposes only. The health information furnished on this site and the interactive responses are not intended to be professional advice and are not intended to replace personal consultation with a qualified physician, pharmacist, or other healthcare professional. You must always seek the advice of a professional for questions related to a disease, disease symptoms, and appropriate therapeutic treatments.
© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.