Collagen and haemoglobin

Question 1

Structure of collagen

Answer 1

Collagen is made up of amino acids in a repeating sequence of 3, one of which is always glycine. The two are commonly proline and hydroxyproline. The primary structure is twisted into a helix held together by hydrogen bonds between parts of the molecules backbone. Three such helices are twisted together to form a triple superhelix held together by hydrogen bonds between the r groups of the amino acid

Question 2

Structure of haemoglobin

Answer 2

It is a globular protein so is soluble in water. It has iron containing harm groups that allow it to bind to oxygen. It has four harm groups, which means it can carry a large amount of oxygen. Its shape changes when it binds to one oxygen group so that it binds to the next one more easily and so on to the fourth. This cooperative binding property means it is good at binding with oxygen when there is a high level of oxygen, but not very good when oxygen levels are low