Question

Na⁺ gradient across the cell membrane drives the transport of most nutrients, including glucose and amino acids, into animal cells. Describe how Na⁺ supports this process. What type of transport is this? Also, explain how Na⁺ gradient across the membrane is maintained.

Answer 1

Co-transport of glucose, amino acids, phosphates is facilitated by sodium uptake. Transport of apical sodium and glucose across cell membrane is mediated by sodium-glucose cotransporter or SGLT. By the action of NaK-ATPase sodium crosses basolateral membrane. Movement of amino acids into the cell is catalyzed by the transporter that acts as an enzyme.

This transport is active transport.

By the action of primary active transport process, when sodium ion concentration is built outside the plasma membrane, an electrochemical gradient is generated. Sodium gradient across the membrane is maintained by ion pump enzymes. By this, ionic solutes are transported across the membrane.