What is the primary composition of a flagellum?

The primary composition of a flagellum is protein. Flagella are long, whip-like structures that protrude from the cell body and are primarily composed of a protein called flagellin. These proteins form the filament structure of the flagellum, allowing for movement by rotating like a propeller. The structural integrity and function of the flagellum depend on these proteins, which are organized in a helical or cylindrical arrangement.

While carbohydrates, lipids, and nucleic acids play important roles in various cellular processes and structures, they do not constitute the primary makeup of flagella. Carbohydrates are more commonly associated with cell wall structures and energy storage, while lipids are essential for membrane formation and energy reserves. Nucleic acids, such as DNA and RNA, are vital for genetic material and protein synthesis but do not directly contribute to the structure or function of flagella. This emphasis on protein composition highlights the importance of flagellin in locomotion and the overall functioning of the flagellum in motile organisms.