Proteins and Collagen Watch
A little extra information if you are heading for A* in A level biology:-
Collagen is rich in the amino acids glycine and proline with the proline residues being hydroxylated to make hydroxyproline.
Also, there are at least 20 different types of collagen;
a) in the sclera of the eye [the outer coat apart from the cornea in front] has collagen fibres of varying diameter, which makes the sclera opaque.
b) the cornea contains Type I and Type IV collagen, and the fibres are arranged in a very symmetrical, ordered lattice of uniform diameter, making the cornea transparent so that light can penetrate and permit vision.
c) collagen is found in skin, tendons, cartilage.
d) Vitamin C (ascorbic acid) is necessary for the synthesis of collagen - hence the slow healing in scurvy (disease due to deficiency of Vitamin C).
Best of luck!
M (specialist biology tutor).