A kinesin is something called a “motor protein.” It’s a friendly chemical that can, essentially, walk different proteins and membranes from one place in a cell to another place to help different cellular processes along. They are kinda cute, and you (and all other eukaryotes) have a bunch of ‘em in you right now!
Purkinje neurons play an essential role in motor function. Here the Purkinje neurons reach their arbor-like dendrites into the molecular layer of the developing cerebellum of a mouse. The mostly green cells at the bottom left are cerebellar granule cells, which relay information from the nervous system to the Purkinje neurons.
Atoms attach to each other when their fuzzy electron clouds interact and shuffle to form more stable arrangements. Notably, atoms with the magic numbers of 2 or 10 or 18 electrons. For this kind of exchange to work some atoms have to give away electrons, while others have to accept them.