Introductory Microbiology (BST 251-3)

<p>To reduce harmful bacteria and extend shelf life (A)</p> Signup and view all the answers

<p>Dry heat (C)</p> Signup and view all the answers

<p>To prevent the glass from shattering (C)</p> Signup and view all the answers

<p>72°C for 15-20 seconds (B)</p> Signup and view all the answers

<p>80°C (B)</p> Signup and view all the answers

<p>Oxidation of cellular components (B)</p> Signup and view all the answers

<p>Dry heat requires a higher temperature. (D)</p> Signup and view all the answers

<p>To ensure even distribution of heat (C)</p> Signup and view all the answers

<p>Glassware and metal instruments (A)</p> Signup and view all the answers

<p>To ensure effective penetration of heat (C)</p> Signup and view all the answers

<p>2 hours (C)</p> Signup and view all the answers

<p>Size of the material being sterilized (C)</p> Signup and view all the answers

<p>To allow for the germination of any remaining spores. (C)</p> Signup and view all the answers

<p>Pasteur filter (A)</p> Signup and view all the answers

<p>To create a sterile environment for working with sensitive materials. (C)</p> Signup and view all the answers

<p>Membrane filter with the smallest pore size (C)</p> Signup and view all the answers

<p>Air movement in a single direction. (C)</p> Signup and view all the answers

<p>All of the above (D)</p> Signup and view all the answers

<p>Sterilizing surgical instruments (C)</p> Signup and view all the answers

<p>0.01 μm (B)</p> Signup and view all the answers

<p>To remove particles larger than 0.3 microns from the air (A)</p> Signup and view all the answers

<p>It can be used to sterilize materials sensitive to heat (B)</p> Signup and view all the answers

<p>Ultraviolet rays (A)</p> Signup and view all the answers

<p>It is commonly used to sterilize work surfaces and air (D)</p> Signup and view all the answers

<p>Ionizing radiation has a higher frequency than non-ionizing radiation (B)</p> Signup and view all the answers

<p>Heat is the most effective method available for destroying all types of microorganisms. (D)</p> Signup and view all the answers

<p>Spores are resistant to drying because they are protected by a thick outer wall. (C)</p> Signup and view all the answers

<p>By denaturing proteins and nucleic acids and disrupting cell membranes (C)</p> Signup and view all the answers

<p>All of the above (D)</p> Signup and view all the answers

<p>All of the above. (D)</p> Signup and view all the answers

<p>The sterilization method should not pose any health risks to humans who will handle or use the sterilized items. (D)</p> Signup and view all the answers

<p>The size and shape of the item to be sterilized. (D)</p> Signup and view all the answers

<p>Using an autoclave to sterilize surgical instruments (C)</p> Signup and view all the answers

<p>Using chlorine bleach (A)</p> Signup and view all the answers

<p>To reduce the number of microorganisms to a safe level (A)</p> Signup and view all the answers

<p>By denaturing proteins of microorganisms (B)</p> Signup and view all the answers

<p>Using ethylene oxide gas (D)</p> Signup and view all the answers

<p>All of the above (D)</p> Signup and view all the answers

<p>A disinfectant is used on inanimate objects, while an antiseptic is used on living tissue (D)</p> Signup and view all the answers

<p>Biocide (A)</p> Signup and view all the answers

A sterilization method involving heating at 100°C for 20 minutes over 3 consecutive days.

Used to sterilize materials that cannot withstand high temperatures.

A process that separates microorganisms from liquids using a material with small pores.

The clear liquid obtained after filtering liquid through sterile materials.

A filter made of compressed asbestos used to sterilize fluids.

A biologically inert filter with pore sizes from 0.01 to 10μm.

Equipment that creates a particle-free workspace using uni-directional airflow.

To provide a sterile working environment by removing contaminants from air.

The process of killing or removing all microorganisms from a product or surface.

The process of destroying harmful pathogens and reducing microorganisms to safe levels.

Sterilization techniques that use physical agents like heat and radiation.

Using high temperatures to kill microorganisms; includes dry heat and moist heat methods.

The use of chemical agents to kill or inhibit the growth of microbes.

Chemical agents that destroy or inhibit the growth of microorganisms.

A substance that effectively sterilizes without damaging the material or surface.

Factors include nature of heat, temperature, time, microorganism count, material type, and microorganism characteristics.

A method of sterilization that causes killing by protein denaturation and oxidative damage, requiring high temperatures.

A technique using direct flame to sterilize tools by igniting microbes and reducing them to ashes.

The complete destruction of infectious materials through combustion, such as needles and syringes.

A widely used dry heat sterilization method, requiring a holding period of 160°C for 2 hours.

The specific high temperature required to effectively sterilize instruments in dry heat methods.

Properties of microorganisms that affect their susceptibility to heat sterilization, including type and number.

Importance of arranging materials to allow free air circulation for effective dry heat sterilization.

High Efficiency Particulate Air filter that removes 90% of particles 0.3 microns or larger.

Purified air flows in parallel lines with uniform velocity over a surface.

High frequency radiation (e.g., X-rays) that sterilizes by damaging DNA and has high penetration power.

Lower frequency radiation (e.g., infrared and UV rays) that does not have enough energy to remove electrons from atoms.

Type of non-ionizing radiation effective for sterilizing surfaces but harmful to human tissue.

The oven must cool slowly for about two hours before opening to prevent glassware from cracking.

A process that sterilizes by denaturation and coagulation of proteins using moisture.

To kill vegetative bacteria, yeast, and molds, heat to 80°C for 5-10 minutes.

Sterilization method using steam and pressure, most effective at 15 psi and 121°C.

Most effective method of sterilization using moist heat under pressure; requires 121°C for 15 minutes.

Autoclaves cannot sterilize substances that repel moisture, like oils and powders.

A process to prevent disease transmission in beverages by heating, such as milk at 63°C for 30 minutes.

Extends milk storage time while preventing the transmission of milk-borne diseases.

A process capable of destroying all microorganisms without harming medical instruments.

Some microorganisms are more resistant to sterilization due to their structure and composition.

Moisture is essential for microbial growth; drying hinders their survival.

Sterilization method using sunlight's UV rays to kill bacteria.

Gradual removal of moisture to inhibit microbial growth, though ineffective on spores.

Factors such as toxicity, cost, and duration affect the choice of sterilization method.

Certain materials can be sterilized at lower temperatures to prevent damage.