Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Antibiotics are chemical substances, such as penicillin, produced by microorganisms that are used to kill or inhibit the growth of bacteria.
Antibiotics work by disrupting specific bacterial processes, such as the synthesis of the bacterial cell wall or the function of ribosomes during protein synthesis.
Antibiotics are ineffective against viruses because viruses do not have their own metabolism or cell structures (like a cell wall) that the drugs can target. Viruses live inside host cells, making them harder to reach without damaging the host.
Antibiotic resistance is a major global health threat. It occurs when a random mutation in bacterial provides resistance to an antibiotic. Through the process of natural selection, these resistant bacteria survive treatment and reproduce.
(Methicillin-resistant Staphylococcus aureus) is a prominent example of a 'superbug' that has developed resistance to many commonly used antibiotics.
To minimize the development of resistant strains, it is essential to avoid using antibiotics for viral infections (like the common cold) and to always complete the full course of prescribed medication to ensure all bacteria are eliminated.
📐Formulae
💡Examples
Problem 1:
Explain why a doctor would not prescribe penicillin to a patient suffering from .
Solution:
is caused by a virus, not a bacterium.
Explanation:
Penicillin specifically targets the synthesis of peptidoglycan in bacterial cell walls. Since viruses lack cell walls and do not perform their own metabolic functions, the antibiotic has no target to act upon.
Problem 2:
Describe how the misuse of antibiotics leads to the evolution of resistant strains like .
Solution:
Misuse creates a selection pressure where only resistant bacteria survive.
Explanation:
If a course of antibiotics is started but not finished, the most susceptible bacteria die, but those with slight resistance (caused by random mutations in their ) may survive. These survivors then reproduce, passing the resistance genes to the next generation via binary fission or horizontal gene transfer.