Definition

Noun: * The movement of a cell or an organism in response to a chemical stimulus. This is a biological process where the direction of movement is determined by the concentration gradient of a specific chemical substance.

Usage

• Chemotaxis is a fundamental biological process. It describes how certain cells or organisms detect and move toward or away from specific chemicals. This term is primarily used in scientific contexts, especially in biology, immunology, and microbiology.
• The word is typically used as an uncountable noun when referring to the general phenomenon.
  • The study focused on bacterial chemotaxis.
• It can be used in a countable sense when referring to specific types or instances.
  • Different chemotaxes are triggered by various attractants.

Examples

Advanced Usage

• Positive chemotaxis: Movement a favorable chemical stimulus (an attractant).
  • The bacteria exhibited positive chemotaxis toward the nutrient source.
• Negative chemotaxis: Movement from an unfavorable or harmful chemical stimulus (a repellent).
  • The protozoa showed negative chemotaxis when exposed to the toxin.

Variants and Related Words

• Chemotactic (adjective): Relating to or involving chemotaxis.
  • The molecule has a strong chemotactic effect on neutrophils.
• Chemoattractant (noun): A chemical substance that induces positive chemotaxis (attracts cells/organisms).
• Chemorepellent (noun): A chemical substance that induces negative chemotaxis (repels cells/organisms).

Synonyms

• Taxis (specifically, chemotaxis is a type of taxis, which is movement in response to any external stimulus).
• Chemical-guided movement.

Related Phrases/Idioms

• Directed migration: A broader term that includes movement guided by various cues, including chemical (chemotaxis), physical (haptotaxis), or other gradients.

Noun

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