Protein Digestion FC Flashcards
Questions
Answers
Where does most protein digestion occur?
Small intestine
Which cells secrete HCL? Which cells secrete pepsinogen?
Parietal cells - HCL
Chief cells - pepsinogen
What ion exchange occurs when H+ enters the gastric pit? When Cl- enters the pit?
K+ moves into parietal cell when H+ moves into pit
K+ transported out of cell with Cl-
What compound is removed from the parietal cell? What takes its place? What does this cause in the blood stream?
HCO3-
Cl-
Alkaline Tide
What is the main purpose of HCL?
Denature proteins to make them more accessible for proteases
Which two hormones stimulate secretion of pepsinogin and HCl?
Histamine and gastrin
Which two hormones stimulate secretion of pancreatic digestive pro-enzymes and enteropeptidase? Where is enteropeptidase located?
Cholecystokinin
Secretin
Villi
What are three major pancreatic pro-enzymes? What activates each into active form?
Trysinogen - enteropeptidase
Chymotrysinogen - trypsin
Procarboxypeptidase - trypsin
What two amino acids does trypsin act on?
Arginine and lysine
What 5 amino acids does chymotrypsin act on?
Tryptophan, Tyrosine, Phenylalanine, Methionine, Leucine
What 3 amino acids does elastase act on?
Alanine, glycine, serine
What are three brush border peptidases? What do they produce?
Endopeptidase, aminopeptidase, dipeptidase
Free AA and di/tri AA
What is transported into cell with FAA? With di/tri?
FAA - Na+
Di/tri - H+
How to FAA diffuse into blood stream?
Passively
What maintains Na+ concentration in mucosal cell?
Na+/K+ atpase pump, pumps Na+ out into blood
What are the essential AA? PVT TIM HALL
Phenyalanine Valine Threonine Tryptophan Isoleucine Methionine histidine Arginine (only in children) Leucine Lysine
What is Hartnup Disease?
Defect transportine neutral AA across intestine
What is Cystinuria?
Congenital defect tranporting cystine
What causes a food allergy?
Proteins enter circulation, provoking formation of antibodies
