What is the function of flagella in prokaryotes? Flagella, also known as whips or tails, play an essential role in the motility of prokaryotic cells. The flagella help the bacteria move towards favorable environments and away from unfavorable ones, which is critical in maintaining an advantage in terms of nutrient acquisition or survival. Flagella are long, hair-like structures that protrude from the cell’s surface. They are composed of a protein called flagellin and are anchored in the bacterial cell wall by a complex motor structure that spans the cell membrane. The rotation of the flagella is powered by the flow of protons or sodium ions across the membrane, generating torque that drives the rotation of the helical structure. The direction of flagellar rotation determines the type of movement displayed by the bacterial cell. Counterclockwise rotation of flagella results in forward movement, whereas clockwise rotation generates tumbling, which allows bacteria to reorient towards a new direction. The flagella of prokaryotic cells exhibit remarkable complexity and diversity, varying in length, number, and arrangement across different species. In addition to their role in motility, flagella are also involved in chemotaxis. Bacteria are attracted or repelled by a range of chemicals in their environment, and they display directional movement towards or away from these cues. This process is mediated by specialized receptors located at the cell’s surface, which detect changes in chemical concentration and transmit signals to the flagellar motor, leading to directional changes in cell movement. Flagella are vital structures that allow prokaryotic cells to navigate their surroundings efficiently. They play a critical role in nutrient acquisition, colonization, and infection, making them an attractive target for the development of novel antimicrobial therapies. References: 1. Berg, H. C. (2003). The rotary motor of bacterial flagella. Annual review of biochemistry, 72(1), 19-54. 2. Berg, H. C., & Brown, D. A. (1972). Chemotaxis in Escherichia coli analysed by threedimensional tracking. Nature, 239(5374), 500-504. 3. Sourjik, V., & Wingreen, N. S. (2012). Responding to chemical gradients: bacterial chemotaxis. Current opinion in cell biology, 24(2), 262-268.
