Zymase
Encyclopedia
Zymase is an enzyme
complex ("mixture") that catalyzes the fermentation
of sugar
into ethanol
and carbon dioxide
. They occur naturally in yeast
s. See alcohol dehydrogenase
.
Zymase was first isolated from the yeast cell in 1897 by a German chemist named Eduard Buchner
who fermented sugar in the laboratory without living cells, leading to 1907 Nobel Prize in Chemistry.
cells and showing that this "press juice" could ferment sugar. This dealt yet another blow to vitalism
by showing that the presence of living yeast cells was not needed for fermentation. The cell-free extract was produced by combining dry yeast cells, quartz
and kieselguhr and then pulverizing the yeast cells with a mortar and pestle. This mixture would then become moist as the yeast cells' contents would come out of the cells. Once this step was done, the moist mixture would be put through a press and when this resulting "press juice" had glucose
, fructose
, or maltose
added, carbon dioxide
was seen to evolve, sometimes for days. Microscopic investigation revealed no living yeast cells in the extract.
One interesting thing is that Buchner hypothesized that yeast cells secrete proteins into their environment in order to ferment sugars, instead of the fermentation occurring inside the yeast cells, which is the actual mechanism.
British chemist Sir Arthur Harden
divided zymase into two varieties (dialyzable and nondialyzable) in 1905.
Some science historians suggest that Eduard Buchner
, in his 1897 work, merely repeated experiments already made by Antoine Béchamp
in 1857. This is not the case : what Buchner obtained with yeast zymase, and without yeast cells, was alcoholic fermentation, while Béchamp had explicitly stated that, in absence of yeast cells, and by use of what he, also, called "zymase", he only obtained sugar inversion, and no alcoholic fermentation. According to K.L. Manchester, what Béchamp called "zymase" was invertase
.
Zymase is also the brand name of the generic enzyme mixture pancrelipase
, a dietary supplement
containing the enzymes amylase
, peptidase, and lipase
. It is sold to help digestion
in people who do not produce enough of their own digestive enzymes.
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...
complex ("mixture") that catalyzes the fermentation
Fermentation (biochemistry)
Fermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. In contrast, respiration is where electrons are donated to an exogenous electron acceptor, such as oxygen,...
of sugar
Sugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...
into ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
and carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
. They occur naturally in 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...
s. See alcohol dehydrogenase
Alcohol dehydrogenase
Alcohol dehydrogenases are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of nicotinamide adenine dinucleotide...
.
Zymase was first isolated from the yeast cell in 1897 by a German chemist named Eduard Buchner
Eduard Buchner
Eduard Buchner was a German chemist and zymologist, awarded with the 1907 Nobel Prize in Chemistry thanks to his work on fermentation.-Early years:...
who fermented sugar in the laboratory without living cells, leading to 1907 Nobel Prize in Chemistry.
Cell-free fermentation experiment
The experiment for which Buchner won the Nobel Prize consisted of producing a cell-free extract of yeastYeast
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...
cells and showing that this "press juice" could ferment sugar. This dealt yet another blow to vitalism
Vitalism
Vitalism, as defined by the Merriam-Webster dictionary, is#a doctrine that the functions of a living organism are due to a vital principle distinct from biochemical reactions...
by showing that the presence of living yeast cells was not needed for fermentation. The cell-free extract was produced by combining dry yeast cells, quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
and kieselguhr and then pulverizing the yeast cells with a mortar and pestle. This mixture would then become moist as the yeast cells' contents would come out of the cells. Once this step was done, the moist mixture would be put through a press and when this resulting "press juice" had glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
, fructose
Fructose
Fructose, or fruit sugar, is a simple monosaccharide found in many plants. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847...
, or maltose
Maltose
Maltose , or malt sugar, is a disaccharide formed from two units of glucose joined with an αbond, formed from a condensation reaction. The isomer "isomaltose" has two glucose molecules linked through an α bond. Maltose is the second member of an important biochemical series of glucose chains....
added, carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
was seen to evolve, sometimes for days. Microscopic investigation revealed no living yeast cells in the extract.
One interesting thing is that Buchner hypothesized that yeast cells secrete proteins into their environment in order to ferment sugars, instead of the fermentation occurring inside the yeast cells, which is the actual mechanism.
British chemist Sir Arthur Harden
Arthur Harden
Sir Arthur Harden FRS was an English biochemist. He shared the Nobel Prize in Chemistry in 1929 with Hans Karl August Simon von Euler-Chelpin for their investigations into the fermentation of sugar and fermentative enzymes....
divided zymase into two varieties (dialyzable and nondialyzable) in 1905.
Some science historians suggest that Eduard Buchner
Eduard Buchner
Eduard Buchner was a German chemist and zymologist, awarded with the 1907 Nobel Prize in Chemistry thanks to his work on fermentation.-Early years:...
, in his 1897 work, merely repeated experiments already made by Antoine Béchamp
Antoine Béchamp
Pierre Jacques Antoine Béchamp was a French biologist. He studied silkworm parasites, and was the first to synthesise Atoxyl.-Biography:...
in 1857. This is not the case : what Buchner obtained with yeast zymase, and without yeast cells, was alcoholic fermentation, while Béchamp had explicitly stated that, in absence of yeast cells, and by use of what he, also, called "zymase", he only obtained sugar inversion, and no alcoholic fermentation. According to K.L. Manchester, what Béchamp called "zymase" was invertase
Invertase
Invertase is an enzyme that catalyzes the hydrolysis of sucrose . The resulting mixture of fructose and glucose is called inverted sugar syrup. Related to invertases are sucrases. Invertases and sucrases hydrolyze sucrose to give the same mixture of glucose and fructose...
.
Zymase is also the brand name of the generic enzyme mixture pancrelipase
Pancrelipase
Pancrelipase is a form of enzyme therapy for the treatment of various digestive disorders, primarily exocrine pancreatic insufficiency. It is a mixture of three digestive enzymes, amylase, trypsin, and lipase, which are normally produced by the pancreas...
, a dietary supplement
Dietary supplement
A dietary supplement, also known as food supplement or nutritional supplement, is a preparation intended to supplement the diet and provide nutrients, such as vitamins, minerals, fiber, fatty acids, or amino acids, that may be missing or may not be consumed in sufficient quantities in a person's diet...
containing the enzymes amylase
Amylase
Amylase is an enzyme that catalyses the breakdown of starch into sugars. Amylase is present in human saliva, where it begins the chemical process of digestion. Food that contains much starch but little sugar, such as rice and potato, taste slightly sweet as they are chewed because amylase turns...
, peptidase, and lipase
Lipase
A lipase is an enzyme that catalyzes the formation or cleavage of fats . Lipases are a subclass of the esterases.Lipases perform essential roles in the digestion, transport and processing of dietary lipids in most, if not all, living organisms...
. It is sold to help digestion
Digestion
Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones....
in people who do not produce enough of their own digestive enzymes.