10.2 AS Level

Antibiotics

8 flashcards to master this topic

Key Concept Flip

How does penicillin weaken bacterial cell walls?

Answer Flip

Penicillin inhibits the enzyme transpeptidase, preventing peptidoglycan cross-linking in bacterial cell walls. This weakens the cell wall, causing the bacterium to lyse due to osmotic pressure, ultimately killing the bacteria.

Key Concept Flip

Why are viruses unaffected by antibiotics like penicillin?

Answer Flip

Viruses lack cell walls and do not perform metabolic processes targeted by antibiotics. Penicillin specifically targets peptidoglycans in bacterial cell walls, structures absent in viruses.

Key Concept Flip

Describe the mechanism of antibiotic resistance in bacteria.

Answer Flip

Bacteria can develop resistance through various mechanisms, including enzymatic degradation of the antibiotic (

Example: beta-lactamase breaking down penicillin), alteration of the antibiotic target site, or reduced membrane permeability to the antibiotic.
Key Concept Flip

Outline how horizontal gene transfer contributes to the spread of antibiotic resistance.

Answer Flip

Horizontal gene transfer, including conjugation, transduction, and transformation, allows bacteria to share resistance genes. This can rapidly disseminate resistance across different bacterial species, exacerbating the problem.

Definition Flip

What are some consequences of widespread antibiotic resistance?

Answer Flip

Consequences include increased treatment failures, longer hospital stays, higher medical costs, and increased mortality rates from infections that were once easily treatable.

Definition Flip

What is an example of a 'superbug' and why is it concerning?

Answer Flip

Methicillin-resistant Staphylococcus aureus (MRSA) is a 'superbug'. It is resistant to many antibiotics, making infections difficult to treat and leading to serious health complications and increased mortality.

Key Concept Flip

Describe steps that can be taken to reduce the impact of antibiotic resistance.

Answer Flip

Strategies include reducing unnecessary antibiotic use (

Example: for viral infections), improving infection control in hospitals, developing new antibiotics, and promoting antibiotic stewardship programs to optimize antibiotic use.
Key Concept Flip

How does antibiotic overuse in agriculture contribute to resistance?

Answer Flip

Routine use of antibiotics in livestock promotes the development and spread of resistant bacteria in animals. These bacteria can then be transferred to humans through the food chain or direct contact, increasing antibiotic resistance in humans.

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10.1 Infectious diseases 11.1 The immune system