co transport

Question 1

define cotransport

Answer 1

transport of one substance coupled with the transport of another substance across the plasma membrane in the same direction through the same carrier protein

Question 2

explain how the transport of sodium ions is involved in the absorption of glucose by epithelial cells

Answer 2

Na+ ions are actively pumped out of epithelial cells and into the blood

they are transported out by the Na+/K+ pump

Na+ concentration in the lumen of gut is higher than in the epithelial cell

Na+ enter by facilitated diffusion

glucose absorbed with Na+ ions against their concentration gradient
( glucose is absorbed with the sodium ions by indirect active transport)

high concentration of glucose in epithelial cell, glucose moves from high in eptihelial cell to low in blood stream by facilated diffusion through a carrier protein