Biased random walk (biochemistry)

In cell biology, a biased random walk enables bacteria to search for food and flee from harm. See also List of basic cell biology topics. Cell biology (also called cellular biology or formerly cytology, from the The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have Bacteria propel themselves with the aid of flagella in a process called chemotaxis, and a typical bacteria trajectory has many charactistics of a random walk. A flagellum ( plural flagella) is a tail-like structure that projects from the Cell body of certain Prokaryotic and Eukaryotic cells and it Chemotaxis, a kind of Taxis, is the phenomenon in which bodily cells bacteria, and other single-cell or Multicellular organisms direct their movements A random walk, sometimes denoted RW, is a Mathematical formalization of a trajectory that consists of taking successive Random steps They move forward for a certain distance, then the course is abrubtly altered by a process called tumbling. The average change of direction is about 60°.

The presence of a food supply gradient adds bias to the random walk and hence the phrase biased random walk. In Vector calculus, the gradient of a Scalar field is a Vector field which points in the direction of the greatest rate of increase of the scalar Bias is a term used to describe a Tendency or Preference towards a particular perspective, Ideology or result especially when the tendency interferes When the bacterium moves away from an attractant like a food source (sugar) the tumbling frequency increases (tumbling, negative chemotaxis). This makes it possible for the bacterium to change course and head back to the food source. The bacterium is also able to steer away from a repellant such as a toxin by reducing the tumbling frequency (running, positive chemotaxis). The bacterium is able to detect a chemical gradient not by monitoring a difference in concentration in head and tail but rather by a temporal sensing mechanism keeping track of concentration through time and space. The biased random walk in bacterium motility may be applied in robotic sensors that are able to find the source of an oil spill in oceans. Motility is a biological term which refers to the ability to move spontaneously and actively consuming energy in the process A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument

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Chemotaxis, a kind of Taxis, is the phenomenon in which bodily cells bacteria, and other single-cell or Multicellular organisms direct their movements

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