Monomers, polymers and carbohydrates

What is a monomer?

A smaller unit that joins with other small units to create a large molecule

What is a polymer?

A long chain of monomers

What happens in a condensation reaction?

Water is removed to form a chemical bond

What happens in a hydrolysis reaction?

Water is added to break a chemical bond and separate molecules

Name three hexose monosaccharides?

Glucose, fructose, galactose

What is the molecular formula of the three hexose monosaccharides?

C6H12O6

What type of bonds are formed when monosaccharides bond?

Glycosidic bonds

Name 3 disaccharides

sucrose, lactose, maltose

what is an isomer?

has the same chemical formula but different arrangement of atoms

what are the two isomers of glucose

Alpha and Beta

What is the structure of an a-glucose and b-glucose

Describe function of starch

used to store a-glucose in plant cells

insoluble - no osmotic effects

large - does not diffuse out of cells

Describe the structure of starch

Amylose - 1,4 glycosidic bonds, helix with intermolecular hydrogen bonds=compact

Amylopectin - 1,4 & 1,6 glycosidic bonds, branched = many terminals ends for hydrolysis into glucose

Describe the functions of glycogen

Used to store a-glucose in animal cells(can be found in plant cells)

insoluble = no osmotic effect & and does not diffuse out of cells

Describe the structure of glycogen

1,4 &1,6 glycosidic bonds, branched = many terminal ends for hydrolysis into glucose, compact

Describe th function of cellulose

To give rigidity to plant cell walls to offer structure and support

Describe the structure of cellulose

polymer of b-glucose, 1.4 glycosidic bonds, straight chain, unbranched, alternate glucose molecules are rotated 180, h-bonds crosslinks between parallel strands form microfibrils = high tensile strength

Describe the benedict’s test for reducing sugars

Add equal volume of benedicts to the sample

heat the mixture in a boiling water bath for 5 mins

positive result = orange and brick red precipitates

Describe the benedict’s test for non-reducing sugars

would give a negative result = blue

hydrolyse the non-reducing sugars in their monomers by adding HCL

heat in a boiling baths for 5 mins

neutralise the mixture using sodium carbonate solution

proceed with the benedict’s test as usual

Describe the test for starch

Add iodine solution

positive result = from orange to blue/black