Sodium Pump

 The sodium pump  is a form of primary active transport.  It can transport materials until saturation.

How does it work?

 The sodium pump creates a gradient.


  It creates a situation where there is a high concentration of sodium outside the cell and a low concentration of sodium inside the cell.

                                                                    

Sodiumpu.gif (1281 bytes)

                  A change in conformation occurs and ATP is broken down to ADP+Pi.
                   K+ ions are brought into the cell.  Na+ ions are exported out of the cell.

                Co-transport occurs when sodium and glucose are transported into the cell.
                The sodium-glucose co-transporter is a form of secondary active transport. 
                It is dependent on transport proteins and takes advantage of high sodium
                        concentrations outside the cell caused by the sodium pump.

na+pump.gif (2357 bytes)


Both glucose and sodium
must be present for
transportation to occur.

As a result of the sodium
ion concentration difference
caused by the sodium pump,
glucose and sodium are
transported into the cell.

Glucose concentrations increase inside the cell.

Finally, a facilitated diffusional pathway transports glucose
back out of the cell and into the blood.

na+pump1.gif (1351 bytes)

BACK to main

to passive versus active transport page