The video aids in understanding that lattice points in a diagram are distinct from the atomic positions themselves.
Three of these dimer units are arranged around a threefold rotation axis to form a hexamer, which takes the shape of an oblate spheroid. H21(1).mp4
Insulin acts as a hormone that regulates blood glucose levels. The video highlights how this massive structure exists as a stable, inactive hexamer in the pancreas before dissociation into biologically active monomers. The video aids in understanding that lattice points
Zn ions, for example, are located directly on the rotation axis. The video highlights how this massive structure exists
These spheroids pack in a hexagonal system (rhombohedral shape) to form a crystal. The packing creates a "threefold symmetry axis" (Zn ions).
The insulin dimer acts as the asymmetric unit within a crystal structure. It is a "giant" unit because it consists of hundreds of atoms.
This content is part of a pedagogical resource focusing on teaching crystallographic symmetry, with related, comprehensive information available on the Bilbao Crystallographic Server. How the ? A deeper look into rhombohedral/hexagonal crystal packing ?