Carbohydrates Key Words Flashcards
What are monomers
Small basic molecular units
What are polymers
They are large complex molecules composed of long chains of monomers
What is a condensation reaction
When two molecules join together with the formation of a new chemical bond and a water molecule is released when the bond is formed
What is a glycosidic bond
A bond between two monosaccarides
What is a disaccaride
When two monosaccarides join together
What is sucrose made up of
Glucose and fructose
What is lactose made up of
Glucose and galactose
What is maltose made up of
Two alpha glucoses
What is hydrolysis
The breaking of a chemical bond between monomers using a water molecule
How do you distinguish between a reducing and non-reducing sugar
- add benedicts reagent to the solution
- heat it in a water bath that has been brought to the boil
- if the test is positive, it will form a coloured precipitate
- if the test is negative, there is still a non reducing sugar present
- break down the solution into monosaccharides
- add dilute HCl
- heat in a water bath that has been brought to the boil
- neutralise with sodium hydrogencarbonate
- add benedicts reagent to the sample
- If the test is positive, it will form a coloured precipitate
- if the test is negative, solution will stay blue, which means it contains no sugars
In benedicts test for reducing sugars, what are the colour changes a reducing sugar can undergo according to the concentration
Blue -> green -> yellow -> orange -> brick red
What is a polysaccaride
2 or more monosaccharides joined together by condensation reaction
What is starch made up of
Two polysaccarides - amylose and amylopectin
What is amylose
Long unbranched chain of alpha glucose
What is amylopectin
Long branched chain of alpha glucose
