2.3 Carbohydrates - Disaccharides and Polysaccharides Flashcards
Monosaccharides combine in larger groups form what?
Polysaccharides.
Pairs of monosaccharides are combined to form a what?
A disaccharide.
Galician links to GLUCOSE to form what?
Maltose
Glucose links to FRUCTOSE to form what?
Sucrose
Glucose links to GALACTOSE forms what?
Lactose
What happens in a condensation reaction when monosaccharides bond? And what is formed?
A molecule of water is REMOVED.
A glycosidic bond forms.
What is hydrolysis?
Te addition of water that causes a breakdown.
In order to test for non-reducing sugars, what must they be broken down into?
Broken dine into its monosaccharide components by hydrolysis.
What is the process in steps of breaking down a non reducing sugar into its monosaccharides by hydrolysis?
- Ground up in water (if but already in liquid form).
- Add equal measure of BENEDICT’S reagent and sample into test tube.
- Place test tube in boiling water for 5 mins. If the colour stays blue, then a reducing sugar is NOT present.
- Add 2cm of food and 2cm of dilute hydrochloric acid to a test tube and place in boiling water for 5 mins.
- Add sodium hydrogencarbonate to this teat tube to neutralise the acid.
- Re-test solution by adding Benedict’s reagent and gently boiling water.
- This will now turn brown/orange if a non reducing sugar is present.
- Add some hydrogencarbonate solution to test tube to neutralise the
Glycosidic bonds are formed by what reaction?
Condensation reaction.
Polysaccharides are very large molecules are insoluble. This makes them suitable for what?
Storage.
Cellulose is not used for storage, but gives support to what?
Plant cells.
From yellow to blue/black.
Start he is detected by its ability to change the colour or iodine from what colour to what colour?
