Enantiostasis
Encyclopedia
Enantiostasis is the ability of an open system
, especially a living organism
, to maintain and conserve its metabolic and physiological functions in response to variations in an unstable environment. Estuarine organisms typically undergo enantiostasis in order to survive with constantly changing salt concentrations. The Australian NSW Board of Studies defines the term in its Biology syllabus as "the maintenance of metabolic and physiological functions in response to variations in the environment".
Enantiostasis is not a form of classical homeostasis
, meaning "standing at a similar level," which focused on maintenance of internal body conditions such as pH, oxygen levels, and ion concentrations. Rather than maintaining homeostatic (stable ideal) conditions, enantiostasis involves maintaining only functionality in spite of external fluctuations. However, it can be considered a type of homeostasis in a broader context because functions are kept relatively consistent.
The term enantiostasis was proposed by Mangum and Towle. It is derived from the Greek
(; opposite, opposing, over against) and (; to stand, posture).
An example of an organism which undergoes enantiostasis in an estuary environment includes-
Open system
Open system may refer to:*Open system , one of a class of computers and associated software that provides some combination of interoperability, portability and open software standards, particularly Unix and Unix-like systems...
, especially a living organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
, to maintain and conserve its metabolic and physiological functions in response to variations in an unstable environment. Estuarine organisms typically undergo enantiostasis in order to survive with constantly changing salt concentrations. The Australian NSW Board of Studies defines the term in its Biology syllabus as "the maintenance of metabolic and physiological functions in response to variations in the environment".
Enantiostasis is not a form of classical homeostasis
Homeostasis
Homeostasis is the property of a system that regulates its internal environment and tends to maintain a stable, constant condition of properties like temperature or pH...
, meaning "standing at a similar level," which focused on maintenance of internal body conditions such as pH, oxygen levels, and ion concentrations. Rather than maintaining homeostatic (stable ideal) conditions, enantiostasis involves maintaining only functionality in spite of external fluctuations. However, it can be considered a type of homeostasis in a broader context because functions are kept relatively consistent.
The term enantiostasis was proposed by Mangum and Towle. It is derived from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
(; opposite, opposing, over against) and (; to stand, posture).
An example of an organism which undergoes enantiostasis in an estuary environment includes-
- The oxygen binding effectiveness of hemocyaninHemocyaninHemocyanins are respiratory proteins in the form of metalloproteins containing two copper atoms that reversibly bind a single oxygen molecule . Oxygenation causes a color change between the colorless Cu deoxygenated form and the blue Cu oxygenated form...
in the blue crab Callinectes sapidus varies according to the concentration of two factors, calcium ion concentration, and hydrogen ion concentration. When these concentrations are varied in the same direction, they have a counterbalancing effect. To stabilize oxygen binding at low ionic concentrations, the crab increases its internal pH (decreasing the hydrogen ion concentration) to allow the hemocyanin to continue to function efficiently.