Porins are located in
A- the outer membrane of gram-negative bacteria
B- he peptidoglycan layer of gram-positive bacteria
C- the cytoplasmic membrane of both gram-negative and gram-positive bacteria
D- the periplasmic space of gram-negative bacteria
A- the outer membrane of gram-negative bacteria
B- he peptidoglycan layer of gram-positive bacteria
C- the cytoplasmic membrane of both gram-negative and gram-positive bacteria
D- the periplasmic space of gram-negative bacteria