Why are proteins so important? What are some of the things that they do?

Protein is required for the growth and maintenance of tissues.
Enzymes are proteins that allow chemical reactions to take place within your body.
Amino acid chains of various lengths form protein and peptides which make up several of your body’s hormones and transmit information between your cells, tissues and organs.
A class is proteins known as fibrous proteins provide various parts of your body with structure, strength and elasticity.
Proteins act as a buffer system, helping your body maintain proper pH values of the blood and other bodily fluids.
Proteins in your blood maintain the fluid balance between your blood and the surrounding tissues.
Proteins form antibodies to protect your body from foreign invaders, such as disease-causing bacteria and viruses.
Hope this helps :)