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...

    Population Regulation in an Ecosystem
    Population Regulation in an Ecosystem

    With regard to the population size of a species and what factors may affect them, two factors have been defined. They ar..

    green leaf - close up view
    Leaves

    Leaves are the major photosynthetic organ of a plant. Apart from that, they are also crucial to water movement. In this ..

    Non-Mendelian Inheritance
    Non-Mendelian Inheritance

    In this tutorial, find out more about certain types of inheritance that does not follow the Mendelian inheritance patter..

    vitamins
    A Balanced Vitamin Diet – Vitamins A – K

    A balanced diet is essential to a healthy organism. Insufficiency or too much of a particular element or compound, such ..

    running freshwater community
    Running Water Freshwater Community Factors

    This tutorial noted some of the physical and chemical factors that provide the framework of a running water community in..

    dinosaurs
    The Dinosaurs

    Dinosaurs represented a major turn in the evolutionary development of organisms on Earth. The first dinosaurs were presu..