Question

What is the flagellar structure in bacteria? Explain the grouping of bacteria on the basis of absence or presence of flagella?

Answer 1

Flagellum are appendages for movement in bacteria. The bacterial flagellum is made up of the protein called flagellin. Its looks like a hollow tube. It is 20-nanometer thick. It has a sharp bend which looks like hook. This hook allows the axis of the helix to point away from the cell. Bacteria can be classified on the basis of flagella. In monotrichous flagella, single polar flagellum is present. For example, Vibrio cholerae. In amphitrichous flagella, single flagellum is present on both sides. For example, Alkaligens faecalis. In lophotrichous flagella, tufts of flagella are present on one or both sides. For example, Spirillum. In peritrichous flagella, many flagella are present all over the body. For example, Salmonella Typhi.