Choose the correct statement. A. End products of fat digestion are absorbed completely in the small intestine and are transported directly into the heart by hepatic portal artery B. Amino acids are the end product of protein digestion and are absorbed in the small intestine by a passive process only. C. Galactose is the end product of milk protein digestion and is absorbed in the small intestine by an active process. D. Microvilli on enterocytes increase the surface area for the absorption of digested food.
Hint: Absorption of Monosaccharides or Absorption of glucose and galactose transpire through active transport. The sodium pump on the cell membrane assists in its active transport. Glucose, galactose as well as fructose are absorbed into the blood capillaries. Galactose is the vastly quickly transported monosaccharide.
Complete answer: The small intestine is the part of the gastrointestinal tract between the stomach and the large intestine where greatly of the digestion of food takes place. The major function of the small intestine is the absorption of nutrients as well as minerals found in food. Digested nutrients pass into the blood vessels in the wall of the intestine through a procedure of diffusion. The inner wall is also known as the mucosa, of the small intestine, is lined with simple columnar epithelial tissue. The small intestinal mucosa also plays a significant role in polluting arginine, proline as well as branched-chain amino acids, along wit perhaps methionine, lysine, phenylalanine, threonine, glycine, and serine in the diet, such that 30–50% of these dietary amino acids are not accessible to extraintestinal tissues. Carbohydrates are primarily digested to glucose, fructose as well as galactose before absorption by the small intestine. Absorption across the brush border along with basolateral membranes of enterocytes is mediated by sodium-dependent and independent membrane proteins. Glucose along with galactose transport across the brush border happens by a Na(+)/glucose (galactose) co-transporter (SGLT1), whereas passive fructose transport is intervened by a uniporter (GLUT5) Intestinal villi are small, finger-like projections that extend into the lumen of the small intestine. Each villus is roughly 0.5–1.6 mm in length (in humans) and has many microvilli projecting from the enterocytes of its epithelium that altogether form the striated or brush border. So, the appropriate answer to the given question is Option (C) - 'Galactose is the end product of milk protein digestion and is absorbed in the small intestine by active process'.
Note: Amino acids as well as monosaccharides which enter the blood capillary network are transmitted away by the blood. But, larger molecules from the digestion of fat join the lacteal. These are then emptied into the lymphatic system, which ultimately releases its contents into the blood system.