Question

what are porins ? explain

Answer 1

any of a class of proteins whose molecules can form channels (large enough to allow the passage of small ions and molecules) through cellular membranes.

Answer 2

Porins are proteins which are located in the outer membrane of Gram-negative bacteria.

The porin channel, a water filled pore through the membrane connecting the exterior to the periplasm, allows the diffusion of small hydrophilic molecules through to the periplasm.

The channel size determines the size of the diffusing molecules