1、Digestive system小鼠小腸吸收細胞電鏡像 9900Mv微絨毛，N細胞核The disaccharidase enzymes are sucrase and lactase. These enzymes sit on the brush border of the intestinal cells. After maltose is produced by the amylase enzyme, sucrase splits the maltose to produce glucose, which is then absorbed in to the blood stream.

2、The sugar in milk is lactose. On the surface of the small intestine is a second enzyme, which splits the lactose in to glucose and galactose. This is the lactose enzyme. The slide shows the most important steps which are involved in cholesterol absorption. Bile acids solubilize dietary and biliary c

3、holesterol in micelles which are phagocytosed by intestinal epithelial cells. The phagocytosed cholesterol is esterified with fatty acid by acyl-CoA cholesterol acyl transferase (ACAT, a microsomal enzyme). Cholesterol esters are used by microsomal triglyceride transfer protein (MTP) to assemble chy

4、lomicrons which are secreted into the lymph. A significant part of cholesterol that is taken up by the intestinal epithelium is secreted back to the intestinal lumen via the ABC transporter A1 (ABC1). Iron abundance states: iron within the enterocyte is trapped by incorporation into ferritin and hence, not transported into blood. When the enterocyte dies and is shed, this iron is lost.Iron limiting states: iron is exported out of the enterocyte via a transporter (ferroportin) located in the basolateral membrane. It the