Elements, whether they are positively charged cations or negatively charged anions, are adsorbed via a facilitated transcellular pathway. This process relies on specialized proteins such as metal transporters, both specific and nonspecific. Additionally, it relies on secondary transporters including transferring or albumin, which help to facilitate their passage across cell membranes. The adsorption of elements occurs via 2 main mechanisms: passive adsorption and active adsorption.