Carbohydrates Flashcards
What are monosaccharides?
Monomers of carbohydrates
Give 3 examples of monosaccharides.
Glucose, galactose and fructose are
common monosaccharides.
What type of bond is formed between two monosaccharides?
Glycosidic
Maltose is made from …
Glucose + Glucose
Sucrose is made from …
Glucose + Fructose
Lactose is made from …
Glucose + Galactose
The difference between an alpha and beta glucose molecule.
On alpha glucose the OH is on the bottom whereas on beta glucose the OH is on the top.
What two polysaccharides are formed from the condensation of alpha glucose units?
Starch and Glycogen
What polysaccharide is formed from the condensation of beta glucose units?
Cellulose
Structure and Function of Glycogen
It is the main storage carbohydrate in animals and fungi
Similar to amylopectin.
Highly branched so it can break down enzymes quicker into glucose which is needed in respiration
Insoluble so doesn’t allow water into the cells
Compact, making it a good storage molecule
Found in the muscles and liver
Structure and Function of Starch
It is the main storage carbohydrate in plants
It contains two types of polymers, amylose and amylopectin.
Its quite branched so glucose can be released efficiently and used for respiration
Compact, making it a good storage molecule
Large and insoluble.
Structure and Function of Cellulose
It is the main component of the plant cell wall
It is made up of unbranched, straight chains having hydrogen bonding between adjacent chains
Test for Sugars
Reducing Sugar:
Add Benedicts solution to a sample
Heat in a water bath
Sample turns orange-brown if a reducing sugar present.
Non-Reducing sugar:
Add dilute HCl to the sample then heat.
Neutralise with sodium hydrocarbonate
Add Benedicts solution to a sample
Heat in a water bath
Sample turns orange-brown if a reducing sugar present.
Test for Starch
An iodine solution can be added to the food.
Foods containing starch will turn from orange-brown to a blue/black colour.
