Osmotic Pressure, Radiation, Microwaves, Chemicals, and Disk Diffusion Method

How is osmotic pressure used? (1)

Use hypertonic solution to Plasmolyse bacterial cells

Is osmotic pressure considered bacteriocidal or bacteriostatic? (1)

Both

What is more resistant to osmotic pressures compared to bacteria? (2)

Mold and yeasts

What does radiation do? (1)

Destroys DNA

Is Radiation Bacteriocidal or Bacteriostatic? (1)

Bacteriocidal

Xrays and gamma rays do what? (1)

Penetrate material

UV snd High energy electron beams are used on what? (1)

On Surfaces

How do microwaves indirectly kill micro organisms? (1)

By heating water

Microwaves contributes to Sterilization or disinfection?

Disinfection

Are chemicals mostly used for disinfection or sterilization? (1)

Disinfection

How is the effectiveness of a chemical determined? (1)

Disk diffusion method

How is disk diffusion method performed? (4)

• Disc of filter paper is soaked in chemical

• Soaked Filter paper is placed on agar plate inoculated with bacteria

• Plate is incubated until bacteria grows

• Zone of Inhibition determines effectiveness