Lactose: Difference between revisions

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Lactose is a disaccharide present in milk. It is made up of the [[Monosaccharides|monosaccharides]] [[Glucose|glucose]] and [[Galactose|galactose]].  The two monosaccarides join via a condensation reaction forming a [[Glycosidic bond|β1-4 glycosidic bond]]. Commonly associated with the [[Lac operon|Lac Operon]] which is a model complex for understanding selective gene [[Transcription|transcription]] control in ''[[Escherichia coli|E. coli]]''.  
Lactose is a disaccharide present in milk. It is made up of the [[Monosaccharides|monosaccharides]] [[Glucose|glucose]] and [[Galactose|galactose]].  The two monosaccarides join via a condensation reaction forming a [[Glycosidic bond|β1-4 glycosidic bond]]. Commonly associated with the [[Lac operon|Lac Operon]] which is a model complex for understanding selective gene [[Transcription|transcription]] control in ''[[Escherichia coli|E. coli]]''.  


In humans the disaccharide is is hydrolysed in humans by the enzyme lactase and by β-galactosidase in bacteria.
In humans the disaccharide is is hydrolysed in humans by the enzyme lactase and by[https://bms.ncl.ac.uk/wiki/index.php/%CE%92-galactosidase β-galactosidase] in bacteria.  


Many adults are unable to drink milk as they are unable to hydrolyse the disaccharide into the two monosaccharides. This condition is called lactose intolerance, or hypolactasia. A deficiency of the enzyme lactase is usually the cause of hypolactasia. 
Many adults are unable to drink milk as they are unable to hydrolyse the disaccharide into the two monosaccharides. This condition is called lactose intolerance, or hypolactasia. A deficiency of the enzyme lactase is usually the cause of hypolactasia.   


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Revision as of 10:14, 2 December 2011

Lactose is a disaccharide present in milk. It is made up of the monosaccharides glucose and galactose.  The two monosaccarides join via a condensation reaction forming a β1-4 glycosidic bond. Commonly associated with the Lac Operon which is a model complex for understanding selective gene transcription control in E. coli.

In humans the disaccharide is is hydrolysed in humans by the enzyme lactase and byβ-galactosidase in bacteria.

Many adults are unable to drink milk as they are unable to hydrolyse the disaccharide into the two monosaccharides. This condition is called lactose intolerance, or hypolactasia. A deficiency of the enzyme lactase is usually the cause of hypolactasia.