Figure 4.4 - Bacterial Flagellum and Flagellar Motor

The ten or so flagella are turned by flagellar motors, propelling Escherichia coli cells at a speed of 10-20 micrometers per second. Each motor is a large complex of proteins that spans the entire cell wall, seen here in cross section. The flagellum, at this magnification, would extend 50 or 100 times the width of this illustration.