Stuff can't remember Flashcards
Name the 4 methods for measuring microbial growth
1) Cell counting
2) Turbidity
3) Dilution Plating
4) Fungal growth
Describe the cell counting method for measuring microbial growth (3)
1)Use a haemocytometer
2)A large microscope slide with accurate grid
What are the limitations of cell counting method (2)
1) Bacteria may be too small to count
2)Cells could be dividing
Describe how microbial growth is measured via measuring turbidity (4)
1) Use a colorimeter
2) Cells in suspension
3) Shake the flask
4) Plot a calibration curve
What are the limitation so of measuring microbial growth via measuring turbidity
1) Dead cells counted
Describe how dilution plating is used to measure microbial growth
1)Take sample from broth culture to agar plate
2) Using aceptic technique
3) Spread evenly onto an agar
4) Incubate at 30 degrees for 24 hours
5) Count the number of colonies
Describe how to measure microbial growth via fungal growth (2)
1) For fungus growing in solid culture: Measure the area
2) For fungus growing in liquid culture: Filter then centrifuge to separate fungus from solution, then dry in oven at 100 degrees, and weight dry mass.
How does the use of vital stain help to count the number of viable cells (2)
1) Vital stain stains only dead cells
2) Not living cells
What are the strengths of measuring microbial growth via measuring turbidity (1)
1) Accurate as counts only viable cells
What is the weakness of measuring microbial growth via measuring turbidity (1)
1) Tediuous as very time consuming
Give an example of Gram positive bacteria
Staphylococcus
Give an example of Gram negative bacteria
Salmonella
Name of bacteria and mode of infection of tuberculosis (2)
1) Mycobacteriu, tuberculosis
2) Secretes enzymes to digest human cells
Name of pathogen and mode of infection of malaria (1)
1) Plasmodium, a protoctist
Name of pathogen of stem rust of wheat
1) Puccinia Graminis, a fungus
