PSL301H1 Lecture Notes - Lecture 32: Intrinsic Factor, Venous Blood, Porphyrin

• School: UTSG
• Department: Physiology
• Course: PSL301H1
• Professor: Michelle French

Document Summary

Certai(cid:374) e(cid:374)zy(cid:373)es are released i(cid:374) i(cid:374)a(cid:272)ti(cid:448)e for(cid:373)s a(cid:374)d the(cid:374) a(cid:272)ti(cid:448)ated i(cid:374) the duode(cid:374)u(cid:373) (cid:449)he(cid:374) it"s safe from autodigestion. There are various forms of transport into the gi tract. Paracellular transport between cells tight junctions prevent this movement, but certain areas allow passage of some materials. Some disease states are characterized by the leakiness of this barrier. Transcytosis (cid:373)aterials too large for tra(cid:374)sporters or (cid:272)ha(cid:374)(cid:374)els, so it"s brought in through endocytosis, vesicular transport across epithelial cells, and then exocytosis releases material on basolateral surface involved in absorption of proteins and peptides. 50% of western diets is carbohydrate starches and sucrose. Long polysaccharides broken up using enzymes in mouth (amylase in saliva) Get digested into various forms disaccharides, which are digested by other enzymes (disaccharidases, specific to those forms: only as monosaccharides can carbohydrates be absorbed into the body. Have to be digested down into monosaccharides glucose, galactose, and lactose. Proteins ingested in polypeptide forms and smaller peptides.