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):
1

Cholesterol Ester Hydrolase

Cleaves FAs from cholesterol esters resulting in free cholesterol and FA

2

Phospholipase A2

Releases FAs from phospholipids producing lysophospholipid and free FAs

3

Colipase

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

4

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

5

Monoglyceride Acylation Pathway

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

*Occurs in smooth ER

6

Phosphatidic Pathway

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

Phosphatidic Acid + Acy CoA => Triglyceride + PO43-

7

Medium-chain FA absorption

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

8

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

9

Gluten Enteropathy

"Celiac Sprue"

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

10

Abetalipoproteinemia

Failure to synthesize Apoprotein B leading to lack of chylomicron formation

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

11

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

12

Osmotic Diarrhea

Excess unabsorbable solute draws water out of intestinal wall

=> diarrhea

13

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

14

Inflammatory Diarrhea

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

15

Main components of flatus

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

16

Pancreatic Lipase

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

17

Gastric Lipase

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