Question

describe diffusion of glucose from intestine to villus epithelium and active transport of sodium ions from nerve cell to outside​

Answer 1

Answer:

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.

Answer 2

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.