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Six facts about proteins
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  • Proteins contain carbon, oxygen, hydrogen, nitrogen and sometimes sulphur.

  • The peptide bonds in proteins can be broken down by hydrolysis. This can be done with dilute acid or a protease enzyme.

  • Proteins structure is described at three levels.

  • The Biuret test can be used to see if proteins are present.
Water is released when the bond between two amino acids forms. Water is added to break the bond. Copper sulphate is added and then sodium hydroxide. A lilac colour indicates that protein is present.