TOPICS: Carbohydrates  Lipids  Proteins  Many proteins are enzymes  Nucleic acids  ATP  Water  Inorganic Ions

Amino acids are the monomers of proteins. The structure of these molecules should be known:

A condensation reaction between two of these amino acids will remove a water molecule and form a peptide bond to create a Dipeptide. Polypeptides are chains of many amino acids joined by the same reaction where this chain is referred to as a primary structure. Secondary structure is where the primary structure is folded into an alpha helix or a beta pleated sheet. Tertiary structure is the further folding of the structure which is held by hydrogen bonds, ionic bonds and disulphide bridges. Quaternary structure is where there is more than one polypeptide chain.

Some proteins are functional and can be primary, secondary, tertiary or quaternary structures. The functions involved are as an energy source, for structure (hair), as enzymes and carrier proteins, hormones, antibodies and are used as a buffer.



Knowing the tests for proteins needs to be known for the exam


  • Add KOH and mix (quantities do not need to be known)
  • Add copper sulphate solution and mix (quantities do not need to be known)


  • Purple is colour is observed