The Bacterial Flagellum

Even under a powerful microscope, it appears tiny and insignificant. It has been compared to a powerful outboard motor attached to a boat. What is the bacterial flagellum?

There are different kinds of flagella, but the bacterial flagellum is probably the most studied. Attached to the cell wall of bacteria, the flagellum rotates, enabling the microorganism to go forward, stop, move in reverse, and change direction. It is estimated that half of all known bacteria are equipped with variations of flagella.

The DNA in the bacteria or microorganism contains the “drawings” of the flagellum and its propulsion unit. The entire assembly consists of about 40 proteins, which can be compared to the parts in a motor. Amazingly, it builds itself in only 20 minutes!

The publication The Evolution Controversy states: “The bacterial flagellum includes a rotary motor that spins around at speeds of 6,000 to 17,000 rpm. Even more remarkable, it can change direction in as little as a quarter turn, and then spin 17,000 rpm in the other direction.” New Scientist magazine calls the bacterial flagellum “a prime example of a complex molecular system—an intricate nano-machine beyond the craft of any human engineer.”

Scientists are baffled by the fact that the tiny bacterial flagellum self-assembles in the exact order that is needed for all 40 parts to fit together properly and function correctly.