ROLES OF ACTIVE TRANSPORT

A. Establish an appropriate intracellular chemical environment (e.g. Na+, K+, acidity-pH)

B. Transport particles across tissue layers, from one body compartment to another (e.g. intestinal mucosa, renal tubule, secretory glands)

Note: Involves asymmetrical membrane transport -- different transport mechanism on opposite sides of the cell

C. Converts metabolic energy to electrochemical potential energy, to be used in

1. electrical transmission of information

2. movement of other substances across membranes -- cotransport (e.g. intestinal glucose absorption)

D. Helps regulate cell volume