Fatty acids, glycerol, and multiglycerides are presented to the enterocytes for absorption in the duodenum and jejunum. In the smooth endoplasmic reticulum glycerol and fatty acids are reassembled into fats characteristic of the host. The membrane bound chylomicron travels from the Golgi apparatus to the cell membrane where the fat droplet is released to the extracellular space. It then diffuses across the basement membrane to the centrally located lymphatic vessel. Lipoproteins are carried to the general circulation via the lymphatics.
Carbohydrate digestion begins in the mouth due to the action of salivary amylase.
Pancreatic amylase completes the job with the aid of other pancreatic enzymes so that mono and disaccharides are available to enterocytes for absorption. Some complex carbohydrates are indigestible in humans and other monogastric species. Termites also host protozoa that digest wood for them. The intestinal mucosal cells synthesize enzymes like sucrase, lactase, and maltase that are present on the surface of the cells. These enzymes break down disaccharides to monosaccharides like glucose, galactose and fructose that are easily absorbed.