mbio lab exam

Question 1

what type of structure is this

Answer 1

MONOTRICHOUS = 1 flagella at 1 pole

Question 2

what structure is this

Answer 2

LOPHOTRICHOUS = several flagella at 1 pole

Question 3

what structure is this

Answer 3

AMPHITRICHOUS = 1 flagella at each pole

Question 4

what structure is this

Answer 4

PERITRICHOUS = flagella all over

Question 5

Flaggela

Answer 5

are very thin and delicate easily broken and can not be seen with oil imersion

Question 6

Motility Media

Answer 6

This media is thick enough to allow motile bacteria to move through it but is too thick for non-motile bacteria to disperse even as they replicate

Tetrazolium salt (TTC)

• TTC is an electron acceptor that is used to detect cellular respiration
• when TTC is reduced by metabolically active bacteria it forms a red, insoluble compound
• in motility media TTC indicates the location of metabolically active/growing bacteria

Question 7

Acid-Fast Stains

Answer 7

Gram stain does NOT work on certain species of bacteria specially bacteria in the genus Nocardia and Mycobacterium.

Nocardia and Mycobacterium species have…

A UNIQUE CELL WALL STRUCTURE

Mycolic acid

(waxy lipid)

CARBOLFUCHSIN = a phenolic-based primary stain that is lipid soluble (i.e., it can more easily penetrate through the waxy cell wall)