1.2 Carbohydrates Flashcards
What bond forms between two monosaccharides?
Glycosidic Bond
What are monosaccharides?
Single unit sugars i.e) Glucose, Fructose, Galactose
What are disaccharides?
Sugars formed by the condensation of two monomers i.e) Glucose+Glucose=Maltose
Glucose+Fructose=Sucrose
Glucose+Galactose=Lactose
How many isomers of glucose are there?
Alpha and Beta. Beta glucose have OH groups diagonally opposite (E isomer) where Alpha has them on the same side (Z isomer)
What are polysaccharides?
Formed by the condensation of many glucose units.
What is Glycogen?
A Glucose forming a branched structure in animals for storage and quick hydrolysis. Similar to amylopectin
What is cellulose?
B Glucose where each molecule alternates and flips to create glycosidic bonds. This causes the formation of microfibrils to add rigidity and strength
What is amylose?
A form of starch formed of A Glucose where it coils into a helix and compacts.
What is amylopectin?
A form of starch formed from A Glucose where it also includes 1,6 and 1,4 glycosidic bonds to create a largely branched chain, great for quickly hydrolysing.
What is the chemical test for reducing sugars?
Heat sample with Benedicts reagent.
If present, the blue will colour red.
What is the chemical test for non reducing sugars?
Heat with dilute Hydrochloric Acid.
Neutralise with Sodium Hydrogen Carbonate
Heat with Benedicts reagent.
If it is Red/Brick Red a non reducing sugar is present
Why is Benedict’s Reagent semi quantitive?
It produces a scale of varying colours between Blue to Red so a quantity of sugar can be assumed.
Why is starch an useful molecule?
Is insoluble so doesn’t affect the water potential of a cell and can be hydrolysed very quickly to provide energy
What is the formula for glucose?
C6H12O6
