Digestion and Absorption of Lipids/Intestinal Secretions Flashcards Preview

S&F IV: Exam One > Digestion and Absorption of Lipids/Intestinal Secretions > Flashcards

Flashcards in Digestion and Absorption of Lipids/Intestinal Secretions Deck (17):

Cholesterol Ester Hydrolase

Cleaves FAs from cholesterol esters resulting in free cholesterol and FA


Phospholipase A2

Releases FAs from phospholipids producing lysophospholipid and free FAs



Non-enzymatic protein secreted by the pancreas that binds to emulsified triglyceride and anchors lipase to bile salts; keeps it close to site of hydrolysis

*Also prevents the bile salts from inhibiting the fnxns of pancreatic lipase


Absorption of lipids

Emulsified products are brought to the unstirred water layer on top of the microvilli where bile salts are lost and the lipid-soluble digestion products diffuse into the enterocyte


Monoglyceride Acylation Pathway

Triglycerides are synthesized from 2-monoglycerides and CoA-fatty acids

*Occurs in smooth ER


Phosphatidic Pathway

2 Acyl CoA + a-glycerophosphate (from hexose metabolism) => Phosphatidic Acid

Phosphatidic Acid + Acy CoA => Triglyceride + PO43-


Medium-chain FA absorption

Do not need micelles to cross luminal barrier and do not need resynthesis to enter the bloodstream


Chlyomicron Formation

Resynthesized triglycerides and fat-soluble vitamins are in the core; phospholipids and cholesterol are the surface

*Are transported out of cell via exocytosis and enter circulation via lacteals


Gluten Enteropathy

"Celiac Sprue"

Allergic reaction to wheat leading to loss of intestinal villi and malabsorption of carbs and protein



Failure to synthesize Apoprotein B leading to lack of chylomicron formation

=>Fats, cholesterol, and PVT TIM HALL not absorbed into blood


Crypt Cell Secretion

Na+/Cl- co-transport brings Cl- in; CFTR channel takes Cl- out into the lumen

*Na+ follows passively thru paracellular mechanisms as does H2O

*Maintains liquidity of chyme in intestine


Osmotic Diarrhea

Excess unabsorbable solute draws water out of intestinal wall

=> diarrhea


Secretory Diarrhea

Activation of Cl- channels leads to increased H2O loss
*Na+/glucose absorption is not inhibited; therefore, treatment is Na+/glucose supplements

*Caused by V. cholerae and E. coli


Inflammatory Diarrhea

Destruction of intestinal cells by Salmonella, Camplyobacter, or C. difficile


Main components of flatus

N2 and sulfur; gas builds up from swallowed air, gas from bacterial metabolism, and diffusion of gas to bloodstream


Pancreatic Lipase

Cleaves FAs from 1 and 3 positions resulting in two FAs and 2-monoglyceride


Gastric Lipase

Cleaves one bond of triglycerides and mixes them to further break up the fats