Answer:
When substances are absorbed through the epithelial cells that line the GI tract into the blood or lymph they are transported vie different mechanisms to different organs of the body where they are used to build up complex new substances, such as the proteins required by our body for normal function.
Step-by-step explanation:
The mechanical and digestive processes convert food into small molecules which are then absorbed by the epithelial cells of the intestinal villi.Large food molecules such as proteins, lipids, nucleic acids, and starches are broken down into smaller molecules which are to be absorbed by the lining of the GI tract.This process is accomplished by enzymes.The absorptive capacity of GI tract is almost endless.Almost all ingested food are absorbed in the small intestine. Although the entire small intestine is involved in the absorption of water and lipids, most absorption of carbohydrates and proteins occurs in the jejunum.Absorption can occur through (1) active transport, (2) passive diffusion, (3) facilitated diffusion, (4) co-transport (or secondary active transport) and (5) endocytosis.