A - 2 - Sugars Flashcards
What elements do all carbohydrates contain?
C, H and O
Carbon, Hydrgen and oxygen
What are the monomers of carbohydrates called?
Monosaccharides
What are the two types of glucose?
Alpha and Beta
What is an isomer?
Molecules with the same chemical formula as each other, but the atoms are connected in different ways
What is a disaccharide?
A molecule formed when two monosaccharides join together
What is the bond formed between two monosaccharides called?
A glycosidic bond
How is a glycosidic bond formed?
Through a condensation reaction
Name three disaccharides
Maltose
Sucrose
Lactose
How is maltose formed?
By condensation of two glucose molecules
How is sucrose formed?
By condensation of a glucose and a fructose molecule
How is lactose formed?
By condensation of a glucose molecule and a galactose molecule
Which test would you use to find a reducing or non reducing sugar?
The Benedict’s test
Describe the Benedict’s test for reducing sugars
1 - Add Benedict’s regent to a sample
2 - Heat it in a water bath that has been brought to the boil
3 - If it is positive it will form a coloured precipitate
How can you measure the solution formed from the Benedict’s test in an accurate way
Filter the solution and weigh the precipitate
OR
Use a colorimeter to measure the absorbance of the remaining Benedict’s regent
Describe the Benedict’s test for Non-reducing sugars
1 - Add dilute hydrochloric acid to the sample
2 - Heat in a water bath that has been brought to the boil
3 - add sodium hydrogencarbonate
4 - Add Benedict’s regent
