dynamic phenomena in cells that can be analyzed on the ultrastructural level comprise so different aspects as ion shifts , conformational changes of macromolecules , membrane particle rearrangements , lipid phase transitions , protein-protein interactions ( notably ligand-receptor interactions , including their sorting and sequestration ) , reversible membrane-to-membrane contacts , membrane fusions , transcellular transport phenomena , restructuring of cytoskeletal elements , ciliary and flagellar beat , cell shape changes , etc .
C0007634
cells
C0010853
cytoskeletal