Introduction to Cilia and Flagella

摘要: Cilia and flagella of eukaryotes are generally long, whiplike appendages extending from the cell body; historically, term flagellum has been used when these structures present singly or in small numbers, whereas cilium occur larger numbers. Typically, a propagates nearly symmetrical bends base to tip organelle, causing fluid which it is beating flow parallel flagellar axis (Fig. 1). move with an asymmetrical beat consisting effective recovery stroke. During stroke large bend formed at cilium, slice rapidly through medium; this followed by stroke, during propagated along ciliary shaft until returns position held before beginning The result pattern that moved surface direction very similar if not identical terms their internal mechanisms movement; indeed, many organisms can both type waveforms. Consequently, most my general comments about organelles may be applied equally well either cilia flagella. eukaryotic should confused prokaryotic flagellum, completely different structure having protein composition mechanism movement (see Macnab, 1987a,b, for reviews). extracellular appendage, intracellular surrounded extension cell’s plasma membrane. It is, course, interesting frequently unique properties membranes raison d’etre book.