摘要: Transport systems for low-molecular-weight solutes are generally divided into two groups: those that driven directly by chemical reactions (e.g. ATP hydrolysis, photolysis), and coupled to gradients established the primary event. Of many ions exist in nature, only (H+ Na+) used as ‘couplers’ cotransport majority of flows. It is no surprise learn both these ‘pumped’ out (or into) their respective compartments~oplasm or internal vesicle--to create electrical ion across specilic membrane.