Digestion Flashcards
Starch
a amylase cleaves 1,4
Isoamylase cleaves 1,6
Keeps teeth clean
Acts in mouth
Lysozyme
cleaves 1,4 glycosidic bonds in bac cell wall
Gram+ bac killed by this enzyme
Lingual Lipase
digests part of dietary fats
HCl
antibac
Denatures proteins
Pepsin
pH 2-2.5
produces oligopeptides
aromatic & large hydrophobic aa
Gastric lipase
short FA & doesn’t need co lipase or bile acid
Total Gastrectomy
Mild digestive problem (protein & fat can still get absorbed)
Risk for intestinal infection
Vit B 12 required (cobalamin)
Pancreas
has bicarb to neturalize pH serine proteases: - trypsin lys & arg COOH - chymotrypsin hydrophobic aa COOH - elastase small aa COOH
*also contains a amylaseP
Carboxypeptidase A & B
A cleaves hydrophobic aa
B cleaves basic aa (lys & arg)
Lipase
triglyceride= 2 monoacylglycerol & 2 FA
needs co lipase & bile acids
Only when touches lipid- water interface
Ser dep
Phospholipases
cleave phospholiipds
Nuclease
cleaves nucleic acids
Pancreatic failure
steatorrhea & generalized lipid malabsorption
Risk of def of fat soluble vitamins!
Intestinal FA binding protein
inside enterocyte FA binds to this enzyme
Re syn triacylglycerol in enterocyte & packed in lipoproteins to be released to lymphatics
Liver & GB
bile salts needed for lipid digestion
Form mixed micelles which carry lipids to mucosal surface
Break up lipid/detergent micelles by peristalsis
W/o= steatorrhea
*bile stones
Lipoproteins
Chylomicrons= transport food lipids & cholesterol from intestine through body
Lipoprotein lipase takes lipids away
Travel via lymphatics
Remnant released into blood & deliver cholesterol to liver.
VLDL, IDL, LDL= transport cholesterol & lipid from liver to otehr tissues
HDL= transport cholesterol & lipids from tissue to liver
Fat malabsorption
No lipase/bile from pancreas/ GB
greasy, malodorous stools
Urine is dark
Sugar proteins
Sucrase= sucrose into gluc & fructose Lactase= lactose into gluc & galactose Glucoamylase= glucose removed fro non red end of starch & maltose & oligosacch from starch Trehalose= gluc & gluc type sugars
Lactose Intolerance
Lactase drops after weaning
Milk/milk products have lactose which when undigested causes:
Flatulence
Abd pain
Diarrhea
Pepsin
from pepsinogen
aa cleaved from amino end, catalyzed by pepsin or low pH
Cleaved peptide acts as pepsin I at neutral pH
Trypsinogen
to trypsin by enteropeptidase in duodenum.
Trypsin activates all pancreatic zymogens (trypsinogen)
Trypsin inhibitor= small polypep binding to trypsin
Acute pancreatitis
zymogens activated w/in pancreases spill into abd cavity & digest pancreas & adipose!
Find amylase & lipase in serum
Chymotrypsinogen
Activation, change in protein structure
Ethanol Detox in liver
Alc dehydrogenase in cytosol
Aldehyde dehydrogenase in mitochondria
Ethanol–> Acetaladehyde–> Acetic acid
2 NADH formed
enz 1- alc dehydrogenase
enz 2- aldehyde “