Bioelectrogenesis is the generation of
electricity by living organisms, a phenomenon that belongs to the science of
electrophysiology. The
nerve impulse is a
bioelectric event. In
biological cells, the
Sodium-Potassium Exchanger maintains a voltage imbalance, or
cell potential difference, between the inside of the cell and its surroundings (see also
ion channel). Also called a
pump, the exchanger is said to be "electrogenic", because it removes three sodium ions for every two ions of potassium it allows in. The process consumes metabolic energy in the form of
ATP. Plant cells also exhibit light-induced electrogenesis. Certain types of bacteria are able to generate electric currents; these are used in
microbial fuel cells and educational kits are available for students and hobbyists. However, the term usually refers to the electricity-generating ability that is in some aquatic creatures, such as the
electric eel and to a lesser extent the
black ghost knifefish. Fish exhibiting such bioelectrogenesis often also possess
electroreceptive abilities (which are more widespread) as part of an integrated electric system. Electrogenesis may be utilized for
electrolocation, self-defense, electrocommunication and sometimes the stunning of prey.