monosaccharides/disaccharides Flashcards
3 quality’s of monosaccharides
sweet
soluble
can crystalise (when taken out of solution)
general structure of carbs
Cn(H20)n
how is a disaccharide formed
condensation reaction (water molecule given off) forming a glycosidic (covalent) bond
what bond does a disaccharide have
glycosidic bond (covalent)
-o-
what glycosidic bonds form straight chains
1-4
what glycosidic bonds form branches
1-6
how is maltose hydrolysed
by maltase to form 2 alpha glucose molecules
how is sucrose hydrolysed
by sucrase to form an alpha glucose and a fructose molecules
how is lactose hydrolysed
by lactase to form an alpha glucose and galactose molecules
test for reducing sugars
add benedict’s reagent
heat mixture in a gently boiling water bath for 5 mins
what is maltose made of
two alpha glucose
what is sucrose made of
alpha glucose and fructose
what is lactose made of
alpha glucose and galactose
test for non reducing sugars
after negative reducing sugars test,
* Boil in hydrochloric acid (to hydrolyse the disaccharide into its monosaccharides)
* Add sodium hydrogencarbonate solution (to neutralise)
* heat in Benedicts reagent
* brick red precipitiate
3 monosaccharides
glucose
fructose
galactose
what are dimers
disaccharides
opposite of a condensation reaction
hydrolysis reaction
which sugars are reducing sugars
maltose and all monosaccharides
what makes a reducing sugar reducing
if it can become oxidised - needs a carboxyl group
define polysaccharide
formed by the condensation reaction of many glucose units
how are glycogen and starch formed
condensation reaction of alpha glucose molecules
how is cellulose formed
condensation reaction of beta glucose molecules
