Bending Moments in Free-Swimming Flagella

Abstract

The bending of a flagellum, such as the flagellum which forms the tail of a sea-urchin spermatozoon, is the result of active mechanochemical processes occurring within the flagellum itself, which cause it to bend actively throughout its length (Gray, 1955; Machin, 1958). To understand how flagella operate, we must understand not only the mechanisms which generate bending, but also the control mechanisms which initiate and coordinate the active bending of different parts of the flagellum in order to generate smoothly propagated bending waves which will efficiently propel a cell.