Which of the following methods is effective at killing bacterial endospores?
Dry heat
Alcohol-based hand sanitizers
Steam under pressure (autoclave)
Boiling in water for 10 minutes
The Correct Answer is C
A. Dry heat: Dry heat at sufficiently high temperature and long exposure (for example, 160–170 °C for prolonged periods) can destroy endospores by oxidizing cellular components, though it requires more time than moist heat.
B. Alcohol-based hand sanitizers: Alcohols are effective against many vegetative bacteria and some viruses but do not reliably destroy bacterial endospores.
C. Steam under pressure (autoclave): Autoclaving uses moist heat at high pressure and temperature (typically 121 °C at 15 psi) to reliably inactivate endospores by denaturing proteins and nucleic acids.
D. Boiling in water for 10 minutes: Boiling kills many vegetative organisms but does not reliably inactivate heat-resistant endospores within that time frame.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
A. Eurytolerant: Refers to organisms that can survive and grow under a wide range of environmental conditions (e.g., temperature, pH, salinity).
B. Stenotolerant: Opposite of eurytolerant; can survive only within a narrow range of conditions.
C. Obligate: Indicates a strict requirement for a particular condition (e.g., obligate aerobe requires oxygen).
D. Facultative: Indicates flexibility with respect to certain conditions (e.g., facultative anaerobes can
Correct Answer is B
Explanation
A. Allosteric inhibition:
Allosteric inhibition involves a molecule binding at a site other than the active site to change enzyme activity; the described action is binding at the active site, so this does not match.
B. Competitive inhibition:
A competitive inhibitor resembles the substrate and competes for binding at the enzyme’s active site; binding prevents the actual substrate from occupying the active site, which fits the description of sulfanilamide.
C. Excitatory allosteric control:
This term implies activation via an allosteric site rather than inhibition at the active site and does not describe substrate mimicry binding the active site.
D. Noncompetitive inhibition:
Noncompetitive inhibitors bind at a different site and reduce enzyme activity regardless of substrate concentration; they do not typically resemble the substrate or compete for the active site.
E. Feedback inhibition:
Feedback inhibition occurs when an end product of a metabolic pathway inhibits an enzyme earlier in that pathway, usually via allosteric binding; the scenario describes direct active-site competition rather than pathway end-product regulation.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.
