Dictionary > Chemotaxis

Chemotaxis

Definition
noun
The directional movement of an organism or a living motile cell in response to certain diffusible chemicals in the environment
Supplement
Chemotaxis is a response of motile cells or organisms in which the direction of movement is affected by the gradient of a diffusible substance. It differs from chemokinesis in that the gradient alters probability ofmotion in one direction only, rather than rate or frequency of random motion. There are two major types of chemotaxis: (1) positive chemotaxis, i.e. the movement is toward a higher concentration of the diffusible substance, and (2) negative chemotaxis, i.e. the movement is in the opposite direction.
Chemotaxis is a kind of taxis, in which bodily cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food (for example, glucose) by swimming towards the highest concentration of food molecules, or to flee from poisons (for example, phenol).
In multicellular organisms,chemotaxis is critical to development as well as normal function. In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis. Certain cells release chemotactic cytokines (or chemokines) to attract motile cells such as T cells towards the direction of the chemokines.
Word origin: chemo– (of chemicals) + Ancient Greek táxis (arrangment, order)
Compare:

See also:

  • chemokine


    You will also like...

    Schematic diagram of bacterial lactose operon
    Gene Action – Operon Hypothesis

    Learn how the way genes control and determine every aspect of the body. This lesson uses lac operon as an example. ..

    ..

    Circulation
    Circulation

    The circulatory system is key to the transport of vital biomolecules and nutrients throughout the body. Learn about the ..

    Golgi apparatus (3-D illustration)
    Role of Golgi Apparatus & Endoplasmic Reticulum in Protein Synthesis

    The endoplasmic reticulum and Golgi apparatus are the organelles involved in the translation step of protein synthesis a..

    Birth Control and Contraception
    Birth Control and Contraception

    Different pregnancy and birth control and contraception strategies are described. Read this tutorial to learn each of th..

    Control of body movement
    Control of Body Movement

    Some of the body movements can be controlled at will, others cannot. The body has a motor program, which is the pattern ..

    Still Water Community Plants
    Still Water Community Plants

    This tutorial looks at the adaptations of freshwater plants for them to thrive in still water habitats. Familiarize your..