Question

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.

Answer 1

The correct answer is - energy from the sodium gradient.

Step-by-step explanation:

The sodium-potassium ATPase requires the energy, to move Na+ out of the lumen of the intestine into the blood, that comes from the ATP hydrolysis. The transport protein maintains the sodium gradient that provides energy and allows for the cotransport of glucose.

Glucose then moves into the blood, So an energy source to maintain sodium gradient is ATP here, which leads to glucose transport from the intestine to the blood. the microvilli on the lumen side of the epithelial cell assist in more uptake of glucose into the epithelial cell by providing the surface area.