Autolysis (biology)
Encyclopedia
In biology, autolysis, more commonly known as self-digestion, refers to the destruction of a cell through the action of its own enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s. It may also refer to the digestion of an enzyme by another molecule of the same enzyme.
The term derives 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;...

 words αυτό ("self") and λύσις ("splitting").

Cell destruction

Autolytic cell destruction is uncommon in living adult organisms and usually occurs in injured cells or dying tissue. Autolysis is initiated by the cells' lysosome
Lysosome
thumb|350px|Schematic of typical animal cell, showing subcellular components. [[Organelle]]s: [[nucleoli]] [[cell nucleus|nucleus]] [[ribosomes]] [[vesicle |vesicle]] rough [[endoplasmic reticulum]]...

s releasing digestive enzyme
Digestive enzyme
'Digestive enzymes' are enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body. Digestive enzymes are found in the digestive tract of animals where they aid in the digestion of food as well as inside the cells,...

s into the cytoplasm
Cytoplasm
The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...

. These enzymes are however released due to the cessation of active processes in the cell, not as an active process. In other words, though autolysis resembles the active process of digestion of nutrients by live cells, the dead cells are not actively digesting themselves as is often claimed and as the synonym self-digestion of autolysis seems to imply. Autolysis of individual cell organelle
Organelle
In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid bilayer....

s can be lessened if the organelle is stored in ice-cold isotonic
Isotonic
The term isotonic may refer to;*Isotonic for the term associated with muscle contraction*An isotone in nuclear physics*Sports drinks are sometimes designed in an isotonic way to assist athletes rehydrate while balancing electrolytes...

 buffer after cell fractionation
Cell fractionation
Cell fractionation is the separation of homogeneous sets, usually organelles, from a heterogeneous population of cells.-Steps:There are three principal steps involved:#Disruption of cells and liberation of organelles.#Macro Filtration...

.

Use

Because primate fetuses grow webbed fingers and toes, autolysis breaks down the webbing as they develop.

In the food industry, autolysis involves killing the yeast
Yeast
Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...

 and encouraging the breakdown of the cells by enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s. It is used to give different flavors. For yeast extract
Yeast extract
Yeast extract is the common name for various forms of processed yeast products made by extracting the cell contents ; they are used as food additives or flavourings, or as nutrients for bacterial culture media. They are often used to create savory flavors and umami taste sensations. Monosodium...

, when this process is triggered by the addition of salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

, it is known as plasmolysis.

In bread
Bread
Bread is a staple food prepared by cooking a dough of flour and water and often additional ingredients. Doughs are usually baked, but in some cuisines breads are steamed , fried , or baked on an unoiled frying pan . It may be leavened or unleavened...

 baking, the term (or, more commonly, its French
French language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

 cognate
Cognate
In linguistics, cognates are words that have a common etymological origin. This learned term derives from the Latin cognatus . Cognates within the same language are called doublets. Strictly speaking, loanwords from another language are usually not meant by the term, e.g...

 autolyse) is best described as the hydration rest following initial mixing of only flour and water that occurs before kneading has fully developed the gluten
Gluten
Gluten is a protein composite found in foods processed from wheat and related grain species, including barley and rye...

; this simplifies the shaping process of the finished dough. The term was coined by French baking professor Raymond Calvel
Raymond Calvel
Raymond Calvel was a bread expert and professor of baking at ENSMIC in Paris, France. Calvel has been credited with creating a revival of French-style breadmaking as well as developing an extensive body of research on improving breadmaking technique, including studies of the differences between...

.

In the making of fermented beverages, autolysis can occur when the must
Must
Must is freshly pressed fruit juice that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace; it typically makes up 7%–23% of the total weight of the must. Making must is the first step in winemaking...

 or wort
Wort
Wort may refer to:* Wort, the liquid created by the mashing of malted barley to use in brewing beer* Worting, Hampshire, a large district and suburb of the town of Basingstoke, in Hampshire, England....

 is left on the lees
Lees (fermentation)
Lees refers to deposits of dead yeast or residual yeast and other particles that precipitate, or are carried by the action of "fining", to the bottom of a vat of wine after fermentation and ageing. The yeast deposits in beer brewing are known as trub...

 for a long time.
In beer brewing
Brewing
Brewing is the production of beer through steeping a starch source in water and then fermenting with yeast. Brewing has taken place since around the 6th millennium BCE, and archeological evidence suggests that this technique was used in ancient Egypt...

, autolysis causes undesired off-flavors. Autolysis in winemaking
Autolysis (wine)
Autolysis in winemaking relates to the complex chemical reactions that take place when a wine spends time in contact with the lees, or dead yeast cells, after fermentation. While for some wines autolysis is undesirable, it is a vital component in shaping the flavors and mouth feel associated with...

 is often undesirable, but in the case of the best Champagnes it is a vital component in creating flavor and mouth feel.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK