Porin channels

Definition

Porin channels are proteins located in the outer membrane of Gram-negative bacteria that allow the passive diffusion of small molecules, including nutrients and waste products. They play a critical role in bacterial resistance to antibiotics by controlling the entry of these drugs.

5 Must Know Facts For Your Next Test

1. Porin channels are integral to the permeability of Gram-negative bacterial cell walls.
2. Alterations or mutations in porin channels can lead to antibiotic resistance by reducing drug uptake.
3. Certain antibiotics, such as beta-lactams and fluoroquinolones, rely on porin channels to enter bacterial cells.
4. The expression levels and types of porin channels can vary among different bacterial species and even within strains.
5. Efflux pumps often work in conjunction with porin channel modifications to confer high-level antibiotic resistance.

Review Questions

• How do porin channels contribute to antibiotic resistance in Gram-negative bacteria?
• Which types of antibiotics typically use porin channels to enter bacterial cells?
• What impact do mutations in porin channels have on drug efficacy?

Related terms

Efflux Pumps: Transport proteins that expel toxic substances, including antibiotics, out of bacterial cells.

Beta-Lactam Antibiotics: A class of broad-spectrum antibiotics that include penicillins and cephalosporins.

Gram-Negative Bacteria: Bacteria characterized by a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides.