claim the interaction of motrin and robitussin can cause heart attacks in children
Active transport. Active transport is the movement of molecules across a cell membrane from a region of their lower concentration to a region of their higher concentrationâin the direction against some gradient or other obstructing factor (often a concentration gradient).
Active transport is the movement of molecules up their concentration gradient , using energy. The concentration of most molecules inside a cell is different than the concentration of molecules in the surrounding environment.