Question

Please answer all questions

Which of the following would be appropriate to use as an antiseptic?

A. Ethanol

B. Ultraviolet light

C. Bleach

D. Phenol

If a piece of heat-sensitive medical equipment must be sterile to be used, which of the following methods would be the best method to achieve this?

Autoclaving

Ionizing radiation

Ultraviolet light

Bleach

An antimicrobial substance that works by disrupting the plasma membrane would be ineffective in treating infections caused by:

Enveloped animal viruses

Prions

Yeast

Gram-positive bacteria

What is the primary mechanism by which ionizing radiation kills microorganisms?

Disruption of the plasma membrane

Damage to genetic material

Inhibition of cellular respiration

Denaturing proteins

A food scientist is trying to calculate how long bagged salad should be exposed to ionizing radiation to reduce the microbial population to 10 or fewer cells. Based on population estimates, the average bag of salad has 10,000,000,000 (ten billion) bacterial cells before treatment. The scientist knows that exposure to ionizing radiation kills 99.9% of the cells in 5 seconds. What is the minimum amount of time the scientist expose each bag of salad to radiation to be sure that there are 10 or fewer living cells in the package?

10 seconds

15 seconds

5 seconds

20 seconds

Based on the cellular structure of Mycobacterium tuberculosis, which of the following disinfectants would be best to use to prevent its growth?

Group of answer choices

Benzalkonium chloride

Phenol

Iodine

Silver nitrate

Which of the following methods of controlling microbial growth is bacteriostatic?

Oligodynamic action

Alcohol

Boiling

Refrigeration

Select all that apply!

Which of the methods of microbial control listed below are biocidal?

Phenol

Ethanol

Hydrogen peroxide

Filtration

Ultraviolet light

Desiccation

Several media types contain heat-sensitive ingredients, including the urease broth used to determine if an organism can digest urea. To use urease media, it must be sterile before inoculation. What is the best way to create sterile urease broth?

Filter the media

Include antibiotics in the media

Autoclave the media

Add formaldehyde to the broth

Answer 1

1. Ethanol is most appropriate to use as an antiseptic and it is used in hand sanitizers and medical wipes or gels. It shows good bactericidal and antifungal effects. Ethanol dissolves the membrane of bacteria and denatures their proteins, without even affecting human skin. 70% of Isopropyl alcohol is used as a disinfectant. Whereas phenol is a potent chemical, in solution it is known as carbolic acid, it causes burning sensation even in small amounts. It is not used as an antiseptic because it can destroy body cells n tissues, although it can be used to clean floor.

2. Autoclaving is most appropriate. It is a sterilization process based on water boiling point under high pressure. Medical items are sterilized as they are placed in a chamber with high pressure and steam sterilizes exterior of equipment. If equipment is heat sensitive, it can be wrapped in paper or cotton wrap. Using ionising radiation can be extremely dangerous if not handled properly and also is quite expensive thus not practical. UV sterilization is too dangerous.

3. Ionising radiation can damage the cell's genetic material as it easily passes through cell and destroy DNA, if not destroy, can cause errors in DNA replication, which can be lethal.

4. 5 seconds

First four are answered by experts. Please post rest in next question.