Excercise #22A ( Microbial Control)

Question 1

Be able to interpret effects of temperature on microbes in water

Answer 1

untreated was not boiled (LAWN)
pasteurized was in boiling water for 1 minute (0)
sanitized was in boiling water for 5 minutes (0)
The longer the boil time the less bacteria there was

Question 2

Be able to recognize and interpret the effects of UV light on bacterial growth.
o What does UV light do to DNA and cells?

Answer 2

UV can cause THYMINEDIMES in DNA to change, cause changes in protein structures

Question 3

Define:
sterilization

Question 4

Define:
disinfectant

Answer 4

used to control the growth of microbes ON NON-LIVING SURFACES (bleach, ammonia)

Question 5

Define:
antiseptic

Answer 5

used to control the growth of microbes ON LIVING SURFACS (wipes)

Question 6

Which is the only method of sterilization that will kill endospores? How does it work?

Answer 6

autoclaving the pressure and high heat causing stem that allow for endospores to be killed

Question 7

What type of disinfectant is each of these? How do they work?

o Gram’s iodine

Answer 7

HALOGEN
powerful oxidizers → inactive proteins
iodine is an antiseptic

Question 8

What type of disinfectant is each of these? How do they work?

o Laboratory disinfectant

Answer 8

SURFACTENT
detergents disrupt cell membranes in high concentrations → cell lysis

Question 9

What type of disinfectant is each of these? How do they work?

o Copper sulfate

Answer 9

METAL IONS
interact with proteins & inactivate them

Question 10

What type of disinfectant is each of these? How do they work?
o Ethanol or isopropanol

Answer 10

ALCOHOLS
denature proteins → kills most types of cells

Question 11

What type of disinfectant is each of these? How do they work?
o carbol fuchsin

Answer 11

PHENOL DERIVATIVES
disrupts cell membranes→ kills cells

Question 12

Be able to interpret results
 What chemical is the organism most sensitive (or most resistant or least sensitive or least resistant) to?

Question 13

THE END