digestion Flashcards
what is digestion
the breakdown of macros molecules inorder to be used by epithelial cells.
proteins to AA
carbs to mono sac
lipids to fatty acids
what’s the role of the stomach
the stomach has a low pH and can denature proteins.
pepsinogen is activated to pepsin
what si the role of the mouth
to introduce a-amylase and homogenize food with a larger SA
what is the role of the pancreas
holds onto NaCO3 inorder to neutralize the stomach and releases digestive enzymes into small intest
what is the role of the gall bladder
release bile salt to assist in the emmuslifiaction of lipds in the stomach
what is Zymogen
the inactive form of a protein which are found in granules attached to the epithial cell wall
pepsinogen
chymotrypsinogen
trypsinogen
porcarboxypeptidase
proelastase
where and how are proteins digested
by proteases. these enzymes do the initial cleaving of the proteins into oligopeptides. this begins in the stomach with pepsinogen. then the oligo moves into the small intestine where pepsin activates the other enzymes to break down into AA and small peptide units via peptidases
how and where are carbs digested
the branch glucose polymer is cleaved by a-amylase (1,4 gly bonds only) to produce maltase, dextrin, and the other common disac. these disac are then further cleaved by enzymes found on the lining of the epithelial cells.
what are the addtional carb cleaving enzy,e that breakdown disac
sucrase and lactase
matlate, a-glucosidase and a-dextrinase
how do the formed mono sac enter the cell?
glu and gal go through the SGLT w/ Na+
Fructose goes though the GLUT 5 (think 5 membered ring)
GLUT2 move everything into the blood
how are lipids prepared for digestion
these are hydrophobic moles Tf the tiraglycerlos are mixed with salts to create an emlusion.
how are lipids digested in the small intest
lipases cleave 2/3 fatty acid chains from the triglycerol. this forms 2 free fatty and 1 mono glycerol. these models form micelles that have a philic interior and ph
how do the digested lipids enter the cell
these models form micelles( philic exterior and phobic interior). They pass into the cell via the FABP to the FATP to the smooth ER where triglyercols are resynthed. they are attached to cholesterol and proteins to form lipoproteins which then pass into the lymph system and then into the blood.
what are chylomicrons
the lipid protiens fromed at the smaooth ER after lipd digestion
what is the metaboslim
the system that transforms moles from one form into another so it can be effectively used by the organism
