Editing Enterocyte (section)

==Function==
The major functions of enterocytes include:<ref>{{cite book |last=Ross |first=M.H. |last2=Pawlina |first2=W. |date=2003 |title=Histology: A Text and Atlas |edition=4th |publisher=Lippincott Williams & Wilkins |isbn=978-0-683-30242-4 |oclc=50334073}}</ref>
*'''Ion uptake''', including [[sodium]], [[calcium]], [[magnesium]], [[iron]], [[zinc]], and [[copper]]. This typically occurs through [[active transport]].
*'''Water uptake'''. This follows the osmotic gradient established by [[NaKATPase|Na+/K+ ATPase]] on the basolateral surface. This can occur [[diffusion|transcellularly]] or [[paracellular transport|paracellularly]].
*'''Sugar uptake'''. Polysaccharidases and [[disaccharidase]]s in the [[glycocalyx]] break down large sugar molecules, which are then absorbed. [[Glucose]] crosses the [[apical membrane]] of the enterocyte using the [[sodium-glucose cotransporter]].  It moves through the [[cytosol]] (cytoplasm) and exits the enterocyte via the [[basolateral membrane]] (into the [[blood capillary]]) using [[GLUT2]]. [[Galactose]] uses the same transport system. [[Fructose]], on the other hand, crosses the apical membrane of the enterocyte, using [[GLUT5]]. It is thought to cross into the blood capillary using one of the other [[glucose transporter|GLUT transporters]].
*'''Peptide and amino acid uptake'''. Peptidases in the glycocalyx cleave proteins to amino acids or small peptides. [[Enteropeptidase]] (also known as enterokinase) is responsible for activating [[pancreatic]] [[trypsinogen]] into [[trypsin]], which activates other pancreatic [[zymogens]]. They are involved in the [[Krebs cycle|Krebs]] and the [[Cori Cycle]]s and can be synthesized with [[lipase]].
*'''Lipid uptake'''. Lipids are broken down by [[Human pancreatic lipase|pancreatic lipase]] aided by [[bile]], and then diffuse into the enterocytes. Smaller lipids are transported into intestinal capillaries, while larger lipids are processed by the [[Golgi apparatus|Golgi]] and [[smooth endoplasmic reticulum]] into lipoprotein [[chylomicra]] and [[exocytosis|exocytozed]] into [[lacteals]].
*'''Vitamin B12 uptake'''. Receptors bind to the [[vitamin B12]]-[[intrinsic factor|gastric intrinsic factor]] complex and are taken into the cell.
*'''Resorption of unconjugated bile salts'''. Bile that was released and not used in emulsification of lipids are reabsorbed in the [[ileum]]. Also known as the [[enterohepatic circulation]].
*'''Secretion of immunoglobulins'''. [[Immunoglobulin A]] from [[plasma cells]] in the [[mucosa]] are absorbed through receptor-mediated [[endocytosis]] on the basolateral surface and released as a receptor-IgA complex into the intestinal lumen. The receptor component confers additional stability to the molecule.