positive chemotaxis

Definition

Target type: biologicalprocess

The directed movement of a motile cell or organism towards a higher concentration of a chemical. [GOC:ai, GOC:bf, GOC:isa_complete]

Positive chemotaxis is a biological process in which an organism or cell moves towards a higher concentration of a chemical attractant. This process is essential for many organisms, including bacteria, fungi, and animals, enabling them to find food, mates, and suitable environments. The movement towards the attractant is mediated by a series of steps that involve the detection of the attractant, signal transduction, and the generation of a directed movement.

The first step in positive chemotaxis is the detection of the attractant by specialized receptors on the cell surface. These receptors bind to the attractant, triggering a cascade of intracellular signaling events. The signaling pathway typically involves a series of proteins that activate each other in a chain reaction, ultimately leading to the activation of motor proteins that drive cell movement.

In bacteria, the most well-studied example of positive chemotaxis is the movement towards sugars, such as glucose. Bacteria have specialized receptors that can detect even small changes in glucose concentration. When glucose binds to these receptors, it triggers a signaling cascade that ultimately leads to the activation of flagellar motors. The flagella are whip-like structures that propel the bacteria through their environment. By rotating in a coordinated manner, the flagella can steer the bacteria towards higher concentrations of glucose.

In animals, positive chemotaxis is also important for a variety of functions, including wound healing, immune responses, and development. For example, white blood cells, which are part of the immune system, use positive chemotaxis to move towards sites of infection where they can destroy pathogens. Similarly, sperm cells use positive chemotaxis to move towards the egg during fertilization.

The mechanism of positive chemotaxis is highly conserved across different species, suggesting its fundamental importance in biological systems. This process plays a crucial role in enabling organisms to navigate their environment, find food, avoid predators, and respond to stimuli. The ability to move towards beneficial chemicals is essential for survival and reproduction, making positive chemotaxis a fundamental biological process.'
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Proteins (13)

Compounds (343)