PetriKey

Concept

Porin

Outer-membrane channel of Gram-negatives

POR-in

Gram negativestructureouter-membranegram-negativeresistanceamr

High-yield clue

Loss of outer-membrane porins reduces antibiotic entry and is a classic contributor to carbapenem resistance.

Overview

A channel-forming protein in the Gram-negative outer membrane that lets small hydrophilic molecules, including some antibiotics, cross into the cell. Loss or mutation of porins reduces drug entry and contributes to resistance.

Classification

  • Outer-membrane protein
  • Beta-barrel channel
  • Selective for small hydrophilic solutes
  • Gram-negative structure

Lab & identification clues

  • OmpF/OmpC channel vocabulary
  • Porin-loss reduced-permeability concept
  • Outer-membrane-barrier vocabulary

Associations

  • Reduced drug uptake resistance
  • Carbapenem-resistance contribution
  • Works with efflux and enzymes

Commonly confused with

  • Efflux pump
  • Beta-lactamase

Your notes

Original microbiology concept summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC/WHO topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment selection, infection-control instructions, or specimen-handling guidance.

OpenStax: Microbiology 2e concept foundationssourceNCBI Bookshelf: Medical Microbiology general conceptssourceCDC: CDC public-health concept pagessource