Search results
Results From The WOW.Com Content Network
Galactose (/ ɡ ə ˈ l æ k t oʊ s /, galacto-+ -ose, "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. [2] It is an aldohexose and a C-4 epimer of glucose. [3] A galactose molecule linked with a glucose molecule forms a lactose molecule.
Of these D-isomers, all except D-altrose occur in living organisms, but only three are common: D-glucose, D-galactose, and D-mannose. The L-isomers are generally absent in living organisms; however, L-altrose has been isolated from strains of the bacterium Butyrivibrio fibrisolvens. [6]
For instance, galactose and glucose are both aldohexoses, but have different physical structures and chemical properties. The monosaccharide glucose plays a pivotal role in metabolism, where the chemical energy is extracted through glycolysis and the citric acid cycle to provide energy to living organisms. Maltose is the dehydration condensate ...
Oligosaccharides of glucose combined with other sugars serve as important energy stores. These include lactose, the predominant sugar in milk, which is a glucose-galactose disaccharide, and sucrose, another disaccharide which is composed of glucose and fructose. Glucose is also added onto certain proteins and lipids in a process called ...
l-Glucose is an organic compound with formula C 6 H 12 O 6 or O=CH[CH(OH)] 5 H, specifically one of the aldohexose monosaccharides. As the l-isomer of glucose, it is the enantiomer of the more common d-glucose. l-Glucose does not occur naturally in living organisms, but can be synthesized in the laboratory.
Two isomers whose molecules are mirror-images of each other are identified by prefixes ' D-' or ' L-', according to the handedness of the chiral carbon atom that is farthest from the carbonyl. In the Fischer projection, that is the second carbon from the bottom; the prefix is ' D -' or ' L -' according to whether the hydroxyl on that carbon ...
Glucose and galactose, for instance, are diastereomers. Even though they share the same molar weight, glucose is more stable than galactose. This difference in stability causes galactose to be absorbed slightly faster than glucose in human body. [4] [5]
Isomers do not necessarily share similar chemical or physical properties. Two main forms of isomerism are structural (or constitutional) isomerism, in which bonds between the atoms differ; and stereoisomerism (or spatial isomerism), in which the bonds are the same but the relative positions of the atoms differ. Isomeric relationships form a ...