bio test revision notes

                                               Charbohydrates

Monosaccharide:- is a single sugar molecule 

general formula is :- (CH2)n 

there are three (n) types of monosaccharides:-

n=3 - triose

n=5 - pentose

n=6 - hexose

isomers are molcules with the same chemical formula but that have different structure. 

examples of isomers are glucose, fructose and galactose 

there are 2 isomers for glucose, and they are alpha glucose and beat glucose. they have the same formula which is C6H12O6 however differnt structure, the only diffeence is that in carbon 1 for alpha the OH molcule is bellow the H and in beta the OH i s above H. ( we can remember this:- ABBA)

Disaccharides:- are 2 monomers joined together by prosses called condensation reaction which eliminates 1 mole water molecue. this formes a glycosidic bond.

examples of disaccharides are :- 

• alpha glucose + glucose ---> maltose 
• glucose + galactose ---> lactose 
• glucose +  fructose ---> sucrose 

Polysaccharides:- this is a polymer meaning it havs 100s -1000s of monomers in a chain joined by glycosidic bon during condensation reaction. this can also be seprater by the use of water and hydrolysis. they are used as storage and  structure:-

• cellulose- fond in the cell wall and prevents it from bursting. it is a beta glucose, adjecent rotated 180 degrees. they are branched with hydrogen bonds crosslinked to form microfibrils.
• glycogen- found in animals in the liver and mucle cells. this is an alpha glucose. it is branched(alpha 1-6) it is…