MCQ Microbiology Answer 47
on
with
0 comments
You are here: Home » Microbiology MCQs » MCQ Microbiology Answer 47
Porins are members of an extended family of transmembrane proteins found in the outer membrane of gram negative bacteria such as E. coli, or in the outer membranes of mitochondria in eukaryotes. The "general" porins provide a simple diffusion pathway across the membrane for molecules less than 1 kDa with little substrate selectivity. This allows most soluble nutrients to enter while excluding dangerous toxins or proteases that might by released by adversary organisms.
The true porins share a common structure, based on a polypeptide of 300-400 amino acids forming a 16 to18 stranded antiparallel beta barrel. The barrel traverses the membrane with its axis normal to the plane of the bilayer, and is arranged as a trimer of three identical subunits.
Tags: Porins, Bacteria, MCQ, Microbiology
Category: Microbiology MCQs
Subscribe to:
Post Comments (Atom)
POST COMMENT
0 comments:
Post a Comment