Page 23 - MNU microbiology theoritical 2025

General Microbiology & Immunology (PM 401) Second level Semester 4 2024/2025

• They are stiff spiral filaments composed of flagellin protein subunits that

extend outward from the cell.

- In Gram-positive bacteria, there are two rings attached to the cytoplasmic

membrane

- In Gram-negative cells, four rings

Four rings Two rings

Types of Flagella arrangement

A- Monotrichous. A single polar flagellum.

B- Amphitrichous. Single flagellum on each of two opposite

ends.

C- Lophotrichous. Several polar flagella located at one or

both poles on the bacteria's surfaces

D- Peritrichious. Many flagella covering the entire cell

surface
NOTE: the term atrichous means there is no flagella

General Microbiology & Immunology (PM 401) theoretical handbook Page 12