Microbial Control and Genetics Exam Review

Flashcards to help review key concepts from the lecture notes on microbial control, antimicrobials, and microbial genetics.

What is the purpose of pasteurization?

To heat substances to destroy pathogens and reduce spoilage organisms.

What is an antiseptic?

A substance used to reduce microbes on living tissue, examples include iodine, alcohol, and betadine.

Define sterilization in microbial control.

Total destruction of all microbes, achieved through methods like steam under pressure or incineration.

What is the Kirby-Bauer method used for?

To test the effectiveness of antibiotics against specific bacterial organisms.

What is 'degerming'?

The mechanical removal of microbes from a surface, such as handwashing with soap.

Describe one mechanism of antibiotic action.

Prevent the bacterial cell wall synthesis.

What does 'bacteriostatic' mean?

Inhibition of new bacterial growth without killing existing bacteria.

What are two examples of nonionizing radiation?

Ultraviolet radiation and visible light.

What is desiccation and how does it affect microbial growth?

Desiccation (drying) inhibits growth by removing water, which is essential for microbial metabolism.

What is the difference between narrow-spectrum and broad-spectrum antibiotics?

Narrow-spectrum antibiotics are effective against a few organisms, while broad-spectrum antibiotics act against many organisms.

List one of the traits of an ideal antimicrobial agent.

It should be fast-acting.

What is the effect of ionizing radiation on microbes?

Destroys DNA and disrupts cellular functions.

What type of mutation is a nonsense mutation?

When a mutation results in an early stop codon, producing an unfinished protein.

What are plasmids and their advantages to bacterium?

Plasmids are small DNA molecules that confer advantages like antibiotic resistance and the ability to produce toxins.

What role does RNA polymerase play in transcription?

It synthesizes RNA from a DNA template.

Explain transformation in microbial genetics.

The uptake of naked DNA from the environment by a bacterial cell.

What causes antibiotic resistance in bacteria?

Resistance can occur through mechanisms such as enzyme production that destroys or deactivates the drug.

How does freezing affect microbial growth?

It inhibits metabolism and reduces growth and reproduction by creating low temperatures.

What is the purpose of disinfectants?

To destroy most microbes on non-living surfaces.

Identify one physical method of microbial control and its function.

Moist heat, which denatures proteins and destroys membranes.

Why are the ribosomes of mitochondria considered similar to bacterial ribosomes?

Because they resemble prokaryotic (bacterial) ribosomes, supporting the endosymbiotic theory.

What is 'desirable' in an effective disinfectant?

Inexpensive and stable during storage.

What are the potential risks of antibiotic treatment?

Allergic reactions can occur, leading to conditions like anaphylactic shock.