1.2 Carbohydrates - Monosaccharides Flashcards
What is the test for reducing sugars?
- 2cm of food sample
- equal amount of Benedict’s reagant
- heat mixture in water bath for 5 minutes
What is a reducing sugar?
A sugar which can donate electrons to another chemical
What colour would the mixture turn if there is a reducing sugar present?
Orange-brown
Name three monosaccharides
Glucose, galactose, fructose
When is a glycosidic bond formed?
When two monosaccharides join together; molecule of water releases
Maltose is formed by condensation of?
Two glucose molecules
Sucrose is formed by condensation of?
A glucose molecule + a fructose molecule
Lactose is formed by condensation of?
A glucose molecule + a galactose molecule
Glycogen and starch are formed by the condensation of?
Alpha-glucose
Cellulose is formed by the condensation of?
Beta-glucose
Benedict’s reagent is used to test for?
Reducing sugars
What elements do all carbohydrates contain?
C, H, O
Why is glucose described as a hexose sugar?
Has 6 carbons
What is an isomer?
Molecules with the same molecular formula as each other, but its atoms are connected in a different way
What’s the difference between an alpha glucose molecule and a beta glucose molecule?
Alpha: H above first Carbon, OH below first Carbon
Beta: OH above first Carbon, H below first Carbon
