Are we looking at absorption at cell level?
What level are you studying?
Transport across intestine epithelium: Sodium and glucose are absorbed using a co-transporter, a sodium dependent co transporter (Glut1), there is a series of changes in conformation following attachment of sodium molecule first to allow glucose to attach to the transporter. So glucose absorption therefore increases when sodium is available to trigger the transporter.
Does this help, or do you need more details?