Proteins

Enzyme - Catalyse all the biochemical reactions in the body.

Structure - Of the body (hair, muscle etc.)

Carry Oxygen - Haemoglobin

Fight Disease - Antibiosis and antitoxins

Chemical messengers - Hormones

(Important parts of cell membrane)

Binding Proteins

Haemoglobin - binds to oxygen in the lungs and releases it in the tissues. CO2 gets bound to haemoglobin in the tissue, is carried in the plasma and released in the lungs.

Antibodies - Proteins with the ability to bind to foreign substances. Immue system responce. Made by White blood cells in response to invasion of foreign substances.

Taste and Smell - Binding proteins on the surface of ceratin cells allow the ability to taste and smell.

Structural Proteins

Collagen - main part of connective tissue ( tendons, ligaments) and muscle.

Elastin - connective tissue with ability to stretch (ears, skin)

Keratin - protein of hair and outer layer of skin. In animals its nails, claws, horns andd feathers. 

(Keratin is deposited in the cells. When the cell is filled up with keratin the cells die and leave keratin behind.)

Contractile Proteins

Actin - thin contractile filaments in muscle

Myosin - thick filaments in muscle

(These two proteins give muscle its appearance and ability to contract)

Structure of Proteins

Polymers - large molecules made up of repeated units called monomers.

Monomers - are amino acids which are chemicals with an amino (-NH2) ending and a carboxylic acid (-COOH) ending

Amino Acids - joined by removing a molecule of water (condensation), thus forming a Peptide bond. 

- Two amino acids - Dipeptide

- Many amino acids - Polypeptide

( A protein is a functional unit made up of one or more polypeptide chains)

Hydrophilic

Water loving