Counterbending in a flagellum macromodel

Abstract

The flagellum is one of the most critical biological compenents in nature; it is a basic feature common to many different types of cells and allows for even the most primitive cells to move around. However, the structure of the flagellum is far from simple. The inner core consists of a 9+2 microtubular structure where nine pairs of microtubules are arranged circumferentially with the last pair running down the center. The interstitial space consists of springy proteins and nexin bridges which radially connect the microtubules. Due to this structural complexity and minuscule size, the physical phenomena that occur within the flagellum itself are not well understood. Furthermore, it has been observed that under beam bending conditions a passive sperm flagellum will exhibit counterbend behavior which cannot be explained by current engineering theories. This study created a macroscopic model of the flagellum which allowed deeper exploration of these phenomena. Analysis of material properties and experiments were used to verify the accuracy of the proposed model.