Penicillins

Definition

Penicillins are a group of antibiotics derived from Penicillium fungi, effective against many Gram-positive bacteria. They inhibit bacterial cell wall synthesis, leading to cell lysis and death.

5 Must Know Facts For Your Next Test

1. Penicillins target the bacterial enzyme transpeptidase, essential for cell wall synthesis.
2. They are primarily effective against Gram-positive bacteria but have limited efficacy against Gram-negative bacteria.
3. Commonly used penicillins include penicillin G, penicillin V, amoxicillin, and ampicillin.
4. Bacterial resistance to penicillin can occur through the production of beta-lactamase enzymes that break down the antibiotic.
5. Penicillins can cause allergic reactions in some individuals, ranging from mild rashes to severe anaphylaxis.

Review Questions

• What mechanism do penicillins use to kill bacteria?
• Why are penicillins more effective against Gram-positive bacteria than Gram-negative bacteria?
• How do bacteria develop resistance to penicillins?

Related terms

Beta-lactamase: An enzyme produced by certain bacteria that breaks down beta-lactam antibiotics like penicillin.

Transpeptidase: A bacterial enzyme targeted by penicillins that is crucial for synthesizing the bacterial cell wall.

Antibiotic Resistance: The ability of bacteria to survive and proliferate despite the presence of an antibiotic designed to kill them or inhibit their growth.