1.7 Growing and Investigating Bacteria Flashcards
What bacteria can be used for lab investigations?
Pure cultures of non-pathogenic bacteria (safe)
Why do scientists grow bacteria?
A culture of microorganisms can be used to find the effect of antibodies and disinfectants on bacteria
What type of microorganisms do investigations need?
Uncontaminated cultures
Where could contamination come from?
The air, the soil, the water around you or your skin
What could happen if the culture is contaminated?
Other bacteria could grow, including pathogens
What is a culture medium?
A liquid or a gel containing nutrients in order to culture microorganisms
Why use a culture medium to grow microorganisms in a lab?
It contains carbohydrates as an energy source, various minerals and sometimes other chemicals
What is a very typical culture medium used in labs?
Agar jelly
What conditions are needed for growing microorganisms?
Warmth and oxygen
Temperature of incubation in schools?
25*C
Temperature of incubation in industry?
35*C
Why do industrial land use 35C instead 25C in schools?
The bacteria will grow at a faster rate so will be easier for industries to experiment on them
How can bacteria be grown?
On agar jelly in a petri dish
Name 2 ways to keep the culture pure.
- kill all bacteria on the equipment
* prevent microorganisms in the air getting into the equipment and the jelly
How can you kill the microorganisms on the equipment?
Pass metal loops through a flame, boil solutions and agar
