Glycosidic bonds and disaccharides Flashcards
The glycosidic linkage connects
two monosaccharides
A glycosidic bond is formed between _________ or ________ group of a saccharide (or a molecule derived from a saccharide) and the hydroxyl group of some compound such as an _______.
the hemiacetal or hemiketal group
alcohol
Glycoside
a substance containing a glycosidic bond
A disaccharide is formed when
2 monosaccharides combine in a dehydration reaction
The most common disaccharides are
maltose, lactose, and sucrose
Maltose (malt sugar or corn sugar) consists of
2 glucose molecules linked by an a-1, 4-glycosidic bond
Where does maltose come from?
partial hydrolysis of starch and also in grains (like barely) by the enzyme amylase, which is in saliva
What is maltose used in?
cereals, candies, and brewing
Lactose (milk sugar)
a disaccharide found in milk and milk products
Lactose makes up
6-8% of human milk
5% of cow’s milk
Why can’t some people digest lactose?
because some people don’t produce enough lactase, the enzyme that hydrolyzes lactose
Many adults become _____ ______ and develop ______ cramps, ______, and _______.
lactose intolerant, abdominal, nausea, diarrhea
How can people combat lactose intolerance?
lactase can be added to milk products (or taken as a supplement)
Sucrose (Table Sugar)
consists of a-D-glucose and B-D-fructose
-it has a B-(1 , 2)-glycosidic bond between carbon 1 of glucose and carbon 2 of fructose
Sucrose is the most ______ _______ and is commercially produced from sugar ______ and sugar ______.
abundant disaccharide, cane, beets
