Monomers, Polymers And Carbohydates

Question 1

Monomers polymers and examples

Answer 1

Monomers are smaller units from which larger molecules are made.
- amino acids
- monosaccharides
- nucleotides
Polymers are molecules made from a large number of monomers joined together
- proteins
- DNA
A condensation reaction joins monomers together to form a chemical bond also involves the elimination of a water molecule.
A hydrolysis reaction breaks a chemical bond between two molecules and involves the use of a water molecule.

Question 2

Monosaccharides

Answer 2

All carbs contain elements C H and O. The monomers that carbs are ,made from are monosaccharides
Glucose = hexose sugar - monosaccharide with six carbon atoms in each molecule
The two types of glucose are alpha and beta these are isomers.

Question 3

Disaccharides

Answer 3

A disaccharide is formed when two monosaccharides are joined together by condensation reaction forming a glycosidic bond and releasing a molecule of water.
Sucrose- fructose + glucose
Maltose- glucose + glucose
Lactose- galactose+ glucose

Question 4

Polysaccharides - STARCH

Answer 4

Cells get energy from glucose. Pants store excess glucose as starch if plants need more energy starch is broken down back into glucose.
Starch = insoluble in water = doesn’t affect water potential
Coiled= compact = useful storage molecule
Alpha glucose molecules joined by alpha 1-4 glycosidic bonds into a long chain . This chain coils.

Question 5

Polysaccharides - GLYCOGEN

Answer 5

Storage of carbohydrate energy in animals
Alpha glucose molecules bonded with alpha 1-4 and 1-6 glycosidic bonds
Branched molecule = rapidly hydrolysed releasing glucose at a faster rate more terminal glycosidic bonds.
Large insoluble molecule does not affect water potential or osmosis particularly important in animals as cells more likely to burst (no cell wall) .

Question 6

Polysaccharides- CELLULOSE

Answer 6

Provides strength and rigidity to plant cell walls
Made of beta glucose joined together by 1-4 glycosidic bonds
Each monomer rotates 180 degrees to form straight chains, the adjacent chains form microfibrils with hydrogen bonds between individual molecules.
Microfibrils twist together to form cell fibres which from a cellulose cell wall.