Problem:

The absorption of glucose by intestinal epithelial cells requires the participation of an apical sodium/glucose co-transporter, a basolateral glucose carrier, and the basolateral sodium pump (Na,K-ATPase). Explain how these proteins work together to generate and exploit the gradients that drive vectorial glucose transport from the apical side to the basolateral side.

Required:

Question: Why is the polarized distribution of these transport proteins required to make this scheme work?

Please provide description of your answer.