Lower GI II Flashcards
Where does digestion of carbs begin?
mouth
What is the role of amylase?
to hydrolyze starch to form sugars
What secretes amylase?
pancreas
Where are disaccharides broken down into monosaccharides?
brush border of the small intestine, monosaccharides absorbed by enterocytes involving SGLT-1
Where does digestion of proteins begin?
stomach
What does pepsin require to be activated from pepsinogen?
acidic environment
Action of pepsin
hydrolyzes proteins to peptides
Where does polypeptide breakdown occur?
small intestine
What initiates the activation of proteolytic enzymes?
enteropeptidase (enterokinase) secreted by duodenal enterocytes
What enzymes secreted in the pancreas are involved in polypeptide breakdown?
trypsin, chymotrypsin, elastase, carboxypeptidase, and amylase
Where does further breakdown of oligopeptides to amino acids occur?
intestinal brush border
Where does digestion of lipids begin?
small intestine
How to lipids enter the small intestine?
as triglyceride droplets
What enzymes are involved in lipid digestion?
pancreatic lipase, pancreatic lipid esterase
What role to micelles play in lipid digestion?
the FA and glycerol released from the TAG breakdown combine with bile salts to form micelles which transport (FA, monoglycerides, glycerol, phospholipids, cholesterol, vit A, K) and are passively absorbed across enterocyte apical plasma membrane into the blood.
