External Structures of Bacteria (Flagella)

What are the 4 most common flagella arrangements of bacteria? (4)

• Monotrichous (Single polar flagellum)

• Lophotrichous (2 Flagellum originating from same pole)

• Amphitrichous (tufts of flagella originating from seperate poles)

• Peritrichous (flagella all over the cell)

What do flagella look like and how do they turn? (3)

Semi rigid, helical, and turn like a propellor

What is a “run” in flagella motility? (1)

When flagella would turn to a new direction and go straight

What is a “tumble”? (1)

when flagella periodically change to a random direction

What is chemotaxis? (1)

The movement toward or away from a stimulant

What is an attractant to flagella? (1)

Nutrients

What is a repellent to flagella? (1)

Toxins

What is an example of attractant chemotaxis? (1)

E.coli will move towards glucose

What can flagellar protein be used for and give an example? (2)

• Can be used to identify a species of bacteria

• eg. E. coli O157:H7 has flagellin protein