Proteins 1) _____ for growth and repair. Proteins contain Carbon, Hydrogen, Oxygen, Nitrogen
and sometimes Sulphur. Proteins are very large molecules, so they 2) _____ directly into our blood; they 3) _____ into amino-acids by the digestive system. There are over 20 different amino-acids.
Our bodies 4) _____ the amino-acids back into protein. When our cells do this, they have to put the amino-acids together in the correct order. There are many millions of possible combinations or sequences of amino-acids; it is our DNA which 5) _____ the information about how to make proteins. Our cells get their amino-acids from the blood. Proteins 6) _____ as a source of energy. When excess amino-acids are removed from the body, the Nitrogen 7) _____ as a chemical called urea. The liver makes urea and the kidney 8) _____ the urea into our urine.
Source: “A Balanced Diet” Retrieved from www.purchon.com/biology/diet.htm
on September 15, 2010
