Microbial Control

Which of the following best describes the general mechanism of action for most disinfectants?

• They increase the pH inside microbial cells, leading to cell death.

• They disrupt the lipid bilayer of microbial cell membranes.

• They act as a nutrient source for microorganisms, promoting their growth.

• They increase the oxygen levels inside cells, leading to oxidative stress.

Tags

NGSS.HS-PS1-2

How do alcohol-based disinfectants primarily kill bacteria?

• By coagulating the cytoplasm

• By inducing mutations in bacterial DNA

• By dehydrating the cells

• By denaturing proteins and dissolving lipids

What is the primary mechanism of action for quaternary ammonium compounds (Quats) as disinfectants?

• Oxidation of cell components

• Disruption of cell wall synthesis

• Disruption of membrane integrity

• Inhibition of protein synthesis

Tags

NGSS.HS-PS1-2

Chlorine-based disinfectants kill microbes by:

• Causing hypermutation

• Interfering with nutrient absorption

• Oxidizing cellular components

• Blocking cellular respiration

How do phenolic disinfectants primarily function?

• By alkylating DNA and RNA

• By disrupting cell walls and membranes

• By inhibiting enzymatic activity

• By precipitating proteins

Which mechanism of action is associated with hydrogen peroxide as a disinfectant?

• Catalyzing the hydrolysis of cell wall components

• Producing free radicals that damage cellular components

• Blocking the synthesis of nucleic acids

• Inhibiting the electron transport chain

Ethylene oxide is used as a disinfectant for heat-sensitive medical equipment because it:

• Causes covalent cross-linking of DNA and proteins

• Induces lipid peroxidation in microbial membranes

• Generates superoxide anions that oxidize cellular components

• Hydrolyzes peptidoglycan in bacterial cell walls

How do biguanides, such as chlorhexidine, exert their antimicrobial effects?

• By catalyzing the formation of disulfide bonds in proteins

• By binding to and disrupting cellular DNA

• By generating hydroxyl radicals

• By disrupting cell membrane integrity

Tags

NGSS.HS-PS1-2

3. A substance that prolongs the shelf-life of food.

• a. additives

• b. conservative

• c. preservative

Tags

NGSS.HS-PS1-5

6.

• a. Disinfectant

• b. Antiseptics

• c. Both

Tags

NGSS.HS-PS1-5