BIOM20002 Lecture 43: 43 Absorption of nutrients A
Document Summary
Plants don"t have as much essential amino acids. Triglycerides: fatty acids determine whether it is oil or fat. Must be transported to right region of the gastrointestinal tract. Lipids, protein, sugars in duodenum and upper jejunum. Must be broken down into small enough molecules to be transported from gi tract lumen to blood stream. But don"t want gut to be too leaky otherwise microflora can penetrate. Nutrients produced (scfa) are absorbed by colonic mucosa which is adapted to use scfa as an energy source. Must be brought into physical contact with the absorptive mucosa. Requires contact between food particles and digestive enzymes. Some enzymes not soluble but are on the membrane of enterocytes. So food needs to be brought up right next to the brush border. Largely depends on enzymes released from exocrine pancreas. Requires reflex circuit for enzymes to be released. Also enzymes in brush border membranes of mucosal epithelial cells.
