What is "chemotaxis"

Chemotaxis \Chem`o*tax"is\, n. Formerly also Chemiotaxis \Chem`i*o*tax"is\ [Chemical + Gr. ? arrangement, fr. ? to arrange.] (Biol.) The sensitiveness exhibited by small free-swimming organisms, as bacteria, zo["o]spores of alg[ae], etc., to chemical substances held in solution. They may be attracted ( positive chemotaxis) or repelled ( negative chemotaxis). -- Chem`o*tac"tic, a. -- Chem`o*tac"tic*al*ly, adv.

1891, coined in German, 1888, by German botanist Wilhelm Pfeffer (1845-1920) from chemo- + Greek taxis "arrangement" (see tactics).

n. (context biology biochemistry English) the movement of a cell or an organism in response to a chemical stimulant

n. movement by a cell or organism in reaction to a chemical stimulus

Chemotaxis (from chemo- + taxis) is the movement of an organism in response to a chemical stimulus. Somatic 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 (e.g., glucose) by swimming toward the highest concentration of food molecules, or to flee from poisons (e.g., phenol). In multicellular organisms, chemotaxis is critical to early development (e.g., movement of sperm towards the egg during fertilization) and subsequent phases of development (e.g., migration of neurons or lymphocytes) as well as in normal function. In addition, it has been recognized that mechanisms that allow chemotaxis in animals can be subverted during cancer metastasis.

Positive chemotaxis occurs if the movement is toward a higher concentration of the chemical in question; negative chemotaxis if the movement is in the opposite direction. Chemically prompted kinesis (randomly directed or nondirectional) can be called chemokinesis.