chemistry of life - proteins

enzymatic protiens

selective acceleration of chemical reaction eg digestive proteins

defensive proteins

protect against disease eg.antibodies

storage proteins

store amino acids and other nutrients for later use, e.g. casein in milk.

transport proteins 

transport of substances eg haemoglobin

hormonal proteins

coordination of an organisms activities eg insulin

receptor proteins

response of a cell to chemical stimulus eg receptors in nerve cells

motor proteins

movement ef myosin

amino acids 

differ in their properties due to differing side chains called R  groups 

secondary structure

the coils and folds result from hydrogen bonds, coil is called an A Helix and a folded is called a B pleated sheet.

tertiary structure

the overall three-dimensional shape of a protein, determined by interactions among R groups.interactions include hydrogen bonds, ionic bonds, hydrophobic interactions and van der waals interactions.

quaternary structure 

two or more polypeptide chains form one macromolecule eg collagen