GENERAL HISTOLOGY

Detailed explanation-1: -As the concentration of glucose builds up in the epithelial cell, it moves downhill into blood by passive, facilitated transport. Fructose, which is not normally present at significant concentrations in blood, is transported by facilitated diffusion.

Detailed explanation-2: -Fructose is specifically and passively transported by the facilitative glucose transporter 5 (GLUT5, Slc2a5) across the intestinal apical membrane and then is transported from the cytosol to the blood by GLUT2 (Slc2a2).

Detailed explanation-3: -Conclusions: Fructose is transported transcellularly by facilitated diffusion and paracellularly (based on lactulose transport) via glucose-activated solution drag.

Detailed explanation-4: -Fructose is transported across the cell membrane of enterocytes via passive transport, in which a membrane protein helps move the fructose without using any ATP molecules. However, both galactose and glucose are transported into the cell by using a sodium-linked secondary active transport system.

Detailed explanation-5: -Fructose diffuses through the mucosa cells of intestine by the process of facilitated diffusion. It uses an integral membrane proteins known as hexose transporter GLUT-2 to move polar or charged substances across the hydrophobic regions of the membrane. So, the correct answer is option B.