PLASTOCYANIN, BALL AND STICK RESIDUES CODED BY TEMPERATURE Plastocyanin is a copper containing protein. Molecules are constantly vibrating. Some atoms in a molecular structure vibrate more strongly than others. Atoms in a main chain are held more rigidly than others and hence do not vibrate as much as atoms in a side chain. These variations in energy are represented by colour-coding. In this particular example, the residues have been colour-coded to show how energetic they are. The residues with high energy are coloured red whilst those which have less energy are shown in blue. The molecular surface is generated using constructive solid geometry. The atomic coordinates are maintained in a relational data base.