Only sugar normaly absorbed in the intestine | MDS entrance preaparations

The only sugar normaly absorbed in the intestine against a concentration gradient is:
A. Xylose      
B. Mannose      
C. Glucose      
D. Ribose

Ans. C 

·   Final products of carbohydrate digestion in intestinal chyme are glucose & fructose.

·   The glucose the glucose transport in intestine is an example of secondary active transport i.e., the energy of glucose transport is provided indirectly by active transport of Na+ out of cell. Because glucose & Na+ share the same contransporter (symport) the sodium dependent glucose transporter (SGLT, Na+ - glucose cotransporter, cross cell membrane 12 times), the high concentration of Na+ on mucosal surface of cells facilitate & low concentration inhibit hexose sugar influx into epithelial cells.