For each series of questions, read carefully to be sure you are addressing the r

ID: 146707 • Letter: F

Question

For each series of questions, read carefully to be sure you are addressing the right

content of the question. As always, if the question applies to more than one, indicate which ones.

Please use the terms provided!

A. We talked about the physical methods of antimicrobial treatment, which include

Pasteurization, filtration, and irradiation. Briefly answer the following questions. If the question

applies to more than one, indicate which ones. Use these terms.

a. Which might be used to disinfect a counter top?

b. Which removes, rather than kills, microbes?

c. Which can be used to reduce the number of microbes in food?

d. Which of the above methods is most appropriate for sterilizing the packages of empty Petri

dishes like we used in the cutting-board lab (into which we poured agar and then incubated)?

B. Ethylene oxide is a gas, hydrogen peroxide is an antiseptic, and gamma-irradiation is a form of

ionizing radiation. Compare and contrast these treatments.

a. Which of the above could you or I apply at home or in the Hartnell microbiology laboratory?

b. Which of the above is used to treat wounds?

c. Which of the above could be used to treat substances that cannot get wet?

d. Which of the above can damage DNA?

C. Compare and contrast refrigeration, pickling (packing in brine, or salt water), and benzoic acid

(a preservative) and their effects on food. Continued on the next page.

a. Which of the above is not used to control growth of microbes in bread?

b. Which controls microbial growth in food by lowering the pH?

c. Which controls microbial growth in food by drawing water out of cells (the purpose of the

technique)?

1) a) irradiation like Uv Ray's can be used to sterlilize or disinfect .

B)pasterurization is used to eliminate pathogens by increase in the temperature and sudden cooling

C) pasteurization is used and irradiation can also be used.

D) by autoclave using dry heat inceresing the temperature and pressure we can sterile the autoclave.

A) ethylene oxide can be applied because it is a gas and safe compared to other so it can be used as a fumigation chemical

B) hydrogen peroxide because it is a liquid and antiseptic and can br used for wound treatment

C) gamma radiation can damage DNA because it is highly mutagenic and cause base damage and DNA can damage

A) pickling salt cannot be used in bread

B) benzoic acid lowers the pH because benzoic acid is acid for acid pH will be low

C) packing in brine or salt water due to osmosis the water will be drawn out of cells which is commonly used in pickling

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.