Microbial Control Methods and Factors

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What is the purpose of biosafety levels in laboratories?

To determine the temperature at which microbes die

To specify the color-coding of lab equipment

To categorize laboratory practices, safety equipment, and facility construction controls required for handling pathogens (correct)

To classify different microbes based on their level of hazard

In biosafety level 3 (BSL-3), what is the key requirement for handling microbes?

Isolation of lab space

Wearing protective suits

Use of safety cabinets (correct)

Handling moderately hazardous agents

What is the primary effect of high temperatures on microbes?

Promote nucleic acid replication

Enhance cell wall structure

Strengthen cytoplasmic membranes

Denature proteins (correct)

What is the significance of Thermal Death Point (TDP) in microbial control?

The minimum temperature needed to kill all cells in a culture in 10 minutes Signup and view all the answers

What is the primary purpose of using high pressure as a method of microbial control?

To disrupt cell structures and functions Signup and view all the answers

What is the main function of desiccation in microbial control?

To remove water from microbes, inhibiting their growth Signup and view all the answers

What type of radiation is described as high-speed subatomic particles freed from their atoms?

Particulate radiation Signup and view all the answers

Which type of radiation damages DNA by ionizing water to release OH?

Ionizing radiation Signup and view all the answers

What type of radiation damages DNA and is specifically mentioned as not being especially antimicrobial when using microwaves?

Nonionizing radiation Signup and view all the answers

Which of the following is NOT mentioned as a principle affecting the effectiveness of chemical methods of microbial control?

Solubility of the disinfectant Signup and view all the answers

What is the main setback of using Phenol (Carbolic Acid) as a disinfectant?

It has an unpleasant odor Signup and view all the answers

Which type of microbial cell component is disrupted by Phenolics as a part of their mechanism of action?

Cell wall Signup and view all the answers

What is the primary reason for halting protein synthesis through action on RNA?

To prevent microbial growth Signup and view all the answers

Which of the following is NOT an ideal characteristic of a microbial control agent?

Expensive Signup and view all the answers

What is the primary purpose of using high-level germicides?

To kill all pathogens, including endospores Signup and view all the answers

Which characteristic does NOT affect the efficacy of antimicrobial methods?

Method of microbial control based on site of medical procedure Signup and view all the answers

What is the primary goal of applying biosafety precautions?

To reduce the risk of exposure to infectious organisms Signup and view all the answers

What is the function of low-level germicides?

Kill vegetative bacteria, fungi, protozoa, and some viruses Signup and view all the answers

What is the recommended optimum concentration of ethanol for killing bacteria and fungi?

70% Signup and view all the answers

Why is pure ethanol (100%) less effective than 70% ethanol for microbial denaturation?

It lacks water to aid in denaturation Signup and view all the answers

How do quaternary ammonium compounds (Quats) primarily affect bacterial cells?

Enhance cell permeability Signup and view all the answers

What is one limitation of using hydrogen peroxide to treat open wounds?

It has catalase activity Signup and view all the answers

How do surface-active agents (surfactants) primarily assist in removing microorganisms?

By decreasing surface tension Signup and view all the answers

Which alcohol is slightly superior to ethanol due to being less volatile and less expensive?

Isopropanol Signup and view all the answers

Which heavy metal is commonly used as a topical cream on burns?

Silver Signup and view all the answers

What is the primary mechanism of action for organic acid food preservatives?

Inhibit metabolism Signup and view all the answers

Which heavy metal compound is used as an algicide?

Copper sulfate Signup and view all the answers