BIOL 1080 Lecture Notes - Lecture 17: Duodenum, Proopiomelanocortin, Chylomicron
Document Summary
Peptide & amino acid transport: intact proteins do not get absorbed into hepatic portal vein! Need to be broken down into amino acids first! They will be recognized as foreign antigens by the immune system! Will also happen if intestinal tract is damaged (causes leakiness) from yeast, chron"s disease: peptides also use sodium for transport! irritants (alcohol/some drugs) Amino acids absorption is therefore saturable! (since it needs sodium to transport) If too much - the rest = peed out! Max effective rate/dose of protein = ~25 grams! (young adults) Older people have almost twice as much! (anabolic resistance! There - liver can break them down / modify them into other amino acids. 5+ grams has stimulatory effect on protein synthesis! (mtor pathway) Fat digestion: emulsifying fat ==> making it soluble with bile! Both hydrophilic and lipophilic! (two ends: breakdown of fat by lipase. Triglycerides = 3 fatty acids on glycerol backbone. Lipase separates them: steps of fat absorption:
