are very large molecules that make up more than half of the
dry matter of cells.
They are some 2 to 20 times bigger than other molecules in cells.
Proteins often determine the shape and structure of cells and
they also have two very important functions:
are proteins made of?
Much like a string of pearls,
a protein is built up from repeating units - in this case
smaller molecules called "amino acids." There are 20 such amino acids in the body.
Nine of these amino acids cannot be made in the human body. These nine
have to be acquired through eating certain foods, such as meat
and certain vegetables.
Proteins differ in the number
and sequence of
amino acids that they contain. That's
where the information code is.