 Metabolism is also dependent on the species of organism; different organisms have slightly different P450 enzymes that metabolize certain PCBs better than others.Looking at the PCB metabolism in the liver of four sea turtle species (green, olive ridley, loggerhead and hawksbill), green and hawksbill sea turtles have noticeably higher hydroxylation rates of PCB 52 than olive ridley or loggerhead sea turtles.This is because the green and hawksbill sea turtles have higher P450 2-like protein expression.