Describe diffusion of glucose from intense to villus epithelial and active transport at of sodium ion from nerve cell to outside
Answers
Answer:
the diffusion of glucose from the intestine to the villus epithelium is by a two-Na+/one-glucose symporter in membranes. The active transport of sodium ions from the nerve cell to the outside is by the sodium-potassium channel.
Explanation:
Glucose is imported against its concentration gradient from the intestinal lumen across the apical surface of the epithelial cells by a two-Na+/one-glucose symporter located in the microvillar membranes.
The glucose is transported into the epithelial cells by common protein carriers via secondary active transport (that is, co-transport with sodium ions).
The monosaccharides leave these cells via facilitated diffusion and enter the capillaries through intercellular clefts.
The sodium-potassium pump carries out a form of active transport. The pumping of ions against their gradients requires the addition of energy from an outside source.
That source is adenosine triphosphate (ATP), the principal energy-carrying molecule of the cell. The sodium-potassium pump in nerve cells pumps Na+ out of the cell and K+ into the cell.
This active transport process works against the concentration gradients of both ions.