Bacteria Morphology and growth Flashcards
1
Q
What are the methods of classifying bacteria?
A
- Size
- Gross structure
- Cell wall structure
- Differential stains
- Morphology
- Growth requirements
2
Q
What is a gram stain?
A
A differential cell wall stain
dividing bacteria into + and -
Gram-positive – BLUE/PURPLE Gram-negative – RED/PINK Negative means the alcohol step damages the outer membrane and allows the BLUE/PURPLE Crystal Violet dye out. The second Safranin/Carbol fuschin dye then stains the cell wall RED/PINK
3
Q
What is an acid fast/ non acid fast stain?
A
Acid Fast
RED (Ziehl–Neelsen : ZN)
or
FLOURESCENT (Auramine)
Non Acid Fast = they do NOT retain (keep fast) the Carbol Fuschin/Auramine stain on cell surface when washed with acid
4
Q
What are the factors affecting growth of bacteria?
A
- Division rate
- Lag phase time
- Oxygen availability
- Carbon availability
- Temperature
- pH
- Inhibitors
- Growth Factors
5
Q
Describe oxygen requirements
A
On image
6
Q
Describe temperature requirements
A
On image
