carbohydrates Flashcards
what is a monomer?
building blocks/subunits joined together to form a polymer
what is a polymer?
a huge molecule made by joining the same monomers together
what is a macromolecule?
a giant molecule made by joining monomers together
what is the difference between a macromolecule and polymer
a polymer is made up of the same monomer while macromolecules may be formed from different types of monomers
what is a monosaccharide and 3 examples ?
one sugar molecule such as
- glucose
- galactose
- fructose
what is a disaccharide and give 3 examples?
two sugar molecules made via a glycosidic bond such as:
- maltose
- sucrose
- lactose
what are sucrose, maltose and lactose made up of?
sucrose= glucose + fructose
lactose= glucose + galactose
maltose=glucose + glucose
what is a polysaccharide and 3 examples?
carbohydrate made up of many monosaccharide via glycosidic bond
1- starch
2- cellulose
3-chitin
example of 3 reducing sugar and 1 non-reducing sugar
reducing sugar
- maltose
- glucose
- fructose
non-reducing
-sucrose
what is the role of covalent bonds?
the bond use to join small molecules together to form a polymer
what are the 2 types of glucose?
alpha-glucose
beta-glucose
describe the structure of alpha-glucose
alpha glucose exist in ring shape with carbons represented by a line except for carbon 6 found on the top and the hydroxyl group is found on the bottom of carbon 1
describe the structure of beta-glucose
beta glucose exist in ring shape with carbons represented by a line except for carbon 6 found on the top and the hydroxyl group is found on the top of carbon 1
what type of reaction is used to make glycosidic bonds?
condensation reaction
what is a glycosdic bond including the overall equation
a glycosidic bond is formed by the removal of a hydrogen atom from one sugar molecule followed by the removal of the hydroxyle group from another to form water. the left over bond of the oxygen is known as the glycosidic bond
overall equation
HO+OH=H^20+O(the glycosidic bond)
explain the formation of a glycosidic bond with reference to disaccharide and polysaccharide
disaccharide
- a hydrogen atom from one sugar molecule is lost and a hydroxyl group from the other to make water. this leaves Oxygen bonded to the 2 sugar molecules. this bond is known as the glycosidic bond
polysaccharide
- made up of many monosaccharide using the glycosidc bond in the same way
what are polysaccharides used for storage and structural purposes?
storage
- glycogen
- starch
structure
- chitin
- cellulose
what is used to make starch?
amylose and amylopectin
describe the structure of what starch is made up of.
amylose
-unbranched straight chain of alpha-1,4 glycosidic bonds
amylopectin
-branched chain of amylose (alpha-1,4glycosidic bond)
and alpha-1,6 glycosidic bonds
what are uses of starch and glycogen?
to release energy
describe the structure of glycogen
similar to amylopectin, where there are alpha-1,4 glycosidic bonds and alpha-1,6 glycosidic bonds. glycogen is more branched due to having more of alpha-1,6 glycosidic bonds
what type of glucose is cellulose made up of?
beta-glucose
describe how cellulose is made and relate it to its function as a cell wall.
by condensation where every second glucose molecule is flipped to form cellulose via glycosidic bonds and a hydrogen bond is formed between the unbranched cellulose molecules to make up the cellulose fibre
why does every second glucose molecule need to be flipped in beta-glucose
to make sure that all the hydroxyl group are aligned to be able to form the glycosidic bond
why is cellulose used as plant cell wall?
cellulose is very strong therefore it is able to withstand the pressure of contents of the cell and not burst
why are reducing sugar called REDUCING sugars
they contain the reducing group which can reduce copper sulphate into copper oxide.
why cant non-reducing sugars be tested only by benedict solution?
the non-reducing sugars do not contain the reducing group as it is used in the formation of the glycosidic bond.
why can non-reducing sugars be tested by benedict solution only after acid hydrolysis
by acid hydrolysis, the glycosidic bonds are broken to form the monomers again, which would contain the reducing group to reduce copper sulphate to copper oxide
What are 3 groups that can be the reducing sugar group
1- aldehyde
2-ketone
3-carbonyl
