Question

What are the building blocks of proteins and how are they used in the body.

Answer 1

I think you want to find out about either amino acids or polypeptides - linking the amino acids together makes polypeptides and proteins are either one or more polypeptide chains. They have various functions from structural eg collagen in bones, the proteins myosin and actin are vital for muscle contraction to ion channels to iron transport - almost every process needs proteins as catalysts (eg enzymes). Have a look at this site for more information:

http://en.wikipedia.org/wiki/Protein