1. Biological Molecules - Carbohydrates Flashcards
Name 3 common monosaccharides?
-Glucose
-Galactose
-Fructose
What forms a glycosidic bond?
A condensation reaction
What is maltose made from?
α-glucose + α-glucose
What is sucrose made from?
α-glucose + α-fructose
What is lactose made from?
α-glucose + β-galactose
What is the difference between α-glucose and β-glucose?
α-glucose has the OH groups in line, β-glucose has the OH groups diagonal
What causes the colour change in a benedicts test?
Blue to brick red indicates electrons have been donated to the Cu2+ ions in benedicts solution.
What is a reducing sugar?
A sugar that donates electrons.
How do you test for reducing sugars?
-Add benedicts to solution
-Heat in a water bath at 80C for 5 minute
-Record colour change
How do you test for non-reducing sugars?
-Add HCl to solution and swirl to mix
-Place in a water bath at 80C for 5 minutes
-Remove and allow to cool
-Add 2 spatulas of sodium hydrogencarbonate
Add benedicts
-Place back in water bath for 5 minutes
-Record colour change
What are the non-reducing sugars?
Sucrose and lactose
What is released during a condensation reaction?
A water molecule
What 2 things happen during a condensation reaction?
-A water molecule is released
-A new covalent bond is formed
What 2 things happen during a hydrolysis reaction?
-Water molecule is used
-A new covalent bond is broken
What are 3 polysaccharides?
Starch
Glycogen
Cellulose
What is starch made from?
α-glucose
What is glycogen made from?
α-glucose