Lipid Digestion Flashcards Preview

Biochem block 3 > Lipid Digestion > Flashcards

Flashcards in Lipid Digestion Deck (33):
0

Lipids are hydrophobic or hydrophilic?

Hydrophobic

1

Because lipids are hydrophobic, how are they typically stored in the body?

Compartmentalized

2

What are the two major functions of lipids?

energy
hydrophobic barrier

3

what are the two minor functions of lipids?

co enzyme qualities
homeostasis

4

what is the function of acid lipases?

target TAG containing short and medium fatty acid chains

5

what are the two specific types of acid lipases?

lingual
Gastric

6

what two mechanical actions emulsify dietary lipids?

mechanical action
bile salts

7

what does pancreatic lipase do?

cleaves fatty acids at carbons 1 and 3

8

what are the 2 products of pancreatic lipase?

2-monoacylglycerol
free fatty acid

9

what does colipase do?

binds to pancreatic lipase (1:1)
anchors the pancreatic lipase and promotes its activity w/ bile salts present

10

what are the 2 forms of dietary cholesterol?

esterfied and nonesterfied (free)

11

what pancreatic enzyme breaks down esterified cholesterol?

cholesterol esterase

12

what are the products of cholesterol esterase?

non-esterified cholesterol and free fatty acids

13

what are the two enzymes that digest phospholipids?

phospholipase A2
lysophospholipase

14

what are the products of phospholipase A2?

free fatty acid
lysophospholipid

15

what are the products of lysophospholipidase?

fatty acid
glycerylphosphoryl base

16

where is CCK released from?

mucosa cells of the duodenum and jejunum

17

what are 3 effects CCK has on the gastrointestinal system?

bile release from the gallbladder
hydrolytic enzyme release from the pancreas
slows down gastric motility

18

what does secretin do?

promotes the release of bicarbonate from the liver and pancreas to the small intestine to create the optimal pH in the small intestines for pancreatic enzyme function

19

lipid digestion in the jejunum generates what?

free fatty acids
free cholesterol
2-monoacylglycerol

20

how are micelles arranged?

hydrophilic outside
hydrophobic inside

21

once lipids are absorbed into the entercytes, where are they processed?

ER

22

what happens to long chain fatty acids in the enterocytes?

converted to active form by fatty-Acyl-Coa synthetase

23

what happens to 2-monoacylglycerol in the enterocyte?

it is converted into TAG by TAG synthase

24

what happens to lysophospholipids in enterocytes?

they are reacylated by acyltransferases to form phospholipids

25

what happens to cholesterol in the enterocyte?

it is esterified

26

what makes up a chylomicron?

CENTER: TAG + cholesteryl ester
OUTSIDE: phospholipids, cholesterol, Apolipoprotein B-48

27

what is lymph that contain chylomicrons called?

chyle

28

what is the route that chyle takes?

lymphatic system to thoracic duct to left subclavian vein to blood

29

what does lipoprotein lipase do?

degrades TAG in the chylomicrons to free fatty acids and glycerol

30

what is the free fatty acid that is released from the chylomicron used for?

taken up by muscle and adipose tissue

31

what is the glycerol used for that is released from chylomicrons?

taken up by the liver for glycolysis or gluconeogenesis

32

how does cystic fibrosis affect the pancreas?

the defective Cl- pump causes a thick mucus to build up in the secretory pumps of the pancreas
this blocks the excretion of pancreatic enzymes