For example, we have one type of amino acid known as glycine, and this contains an age group, while another amino acid contains this side chain group that is known as cysteine. And these two amino acids have different functionalities. For example, cysteine is important in forming these linkages known as disulfide bridges. And we'll talk much more about what these are in a future electra. So basically, different functional groups have different capabilities and different reactivities. And the arrangement and sequence of these amino acids and their functional groups helps determine the ways in which the proteins are actually involved in helping the different types of reactions that exist inside our body.