Glucose and sodium move from the lumen of the small intestine into the blood via transport proteins in the epithelial cells lining the small intestine (Figure 1).

Based on Figure 1, describe the direct source of energy used to move glucose into the epithelial cell from the intestinal lumen.

Explain how this system maximizes glucose absorption from the intestinal lumen into the epithelial cells and from the epithelial cells into the blood.