Page 33 - The Cell and Its Components

Different Types of Proteins
There are literally thousands of different types of proteins
in our bodies. Here are a few of the major groups and
functions of proteins:

 Structural - Many proteins provide structure for our
bodies. This includes collagen which is found in
cartilage and tendons.
 Defensive - Proteins help protect us from
diseases. They make up antibodies that fight off
foreign invaders such as bacteria and other toxic
substances.
 Transport - Proteins can help to carry essential
nutrients around our bodies. One example is
hemoglobin which carries oxygen in our red blood
cells.
 Catalysts - Some proteins, such as enzymes, act
as catalysts to assist in chemical reactions. They
help us to break up and digest our food so it can
be used by our cells.

Interesting Facts about Proteins and Amino Acids
 We get amino acids from basic foods such as
chicken, bread, milk, nuts, fish, and eggs.
 Hair is made up of a protein called keratin.
 A special kind of RNA called transfer RNA moves
the amino acids to the ribosome. It is abbreviated
as tRNA where the "t" stands for transfer.
 The bonds that link the amino acids in a protein
together are called peptide bonds.
 The arrangement and type of different amino acids
along the protein strand determines the function of
the protein.