Fat Digestion Module (Quiz)

Question 1

the fat that comes from our diet is mostly in the form of

which makes up the majority of fats

Answer 1

• triglycerides
• cholesterol
• phospholipids
• triglycerides

Question 2

basic structure of triglyceride

Answer 2

• glycerol + 3 fatty acids

Question 3

the fatty acid chains make up the hydro________ portion of the lipid and the glycerol makes up for the hydro________ portion of the lipid

Answer 3

• phobic

- philic

Question 4

_______ are the backbone structure for all lipids and the target of enzymes that break down lipids in GI tract

Answer 4

• triglycerides

Question 5

which are the essential vitamins that come from dietary fat

Answer 5

• ADEK

Question 6

intestinal lining made up of multiple ______

Answer 6

• villi

Question 7

within each villus there is a series of _____ as well as a single ________ which drains into the lymphatic system

Answer 7

• capillaries

- single lacteal

Question 8

epithelium of each individuals villus contains a brush border of ________ which increases the absorptive surface area of intestines

Answer 8

• microvilli

Question 9

the challenge for lipids in the intestinal lumen

Answer 9

• have to make them hydrophilic so they can be digested by hydrophilic enzymes and eventually absorbed

Question 10

stages of lipid digestions

Answer 10

• emulsification
• lipolysis
• micellization
• packaging and transport of chylomicrons

Question 11

what is emulsification

Answer 11

• breaking up large fat globules into smaller particles

Question 12

where is emulsification initiated?

Answer 12

• in the small intestine

Question 13

purpose of emulsification

Answer 13

• increase surface area of fat particles so they can be broken down in later stages

Question 14

bile is mostly composed of _________

Answer 14

• water

Question 15

what is the predominant solid portion of bile

Answer 15

• bile salts

Question 16

importance of bile salts being strongly ionized

Answer 16

• allows them to be soluble

Question 17

main phospholipid of bile

Answer 17

• lecithin

Question 18

which parts of the bile are soluble in water

Answer 18

• polar parts of bile salts and lecithin molecules

Question 19

how do we make the fat soluble in water?

Answer 19

• hydrophilic bile acid on top

- lecithin poking out

Question 20

hydrolysis of lipids is done by cleavage of ______ bond in triglycerides

Answer 20

• ester bond

Question 21

_______ lipase is found in saliva

Answer 21

• lingual lipase

Question 22

________ lipase is secreted by ________ cells in the stomach

works best where

Answer 22

• gastric lipase
• chief cells
• acidic environments

Question 23

problem with gastric lipase

Answer 23

• only cleave one side of the glycerol molecule

Question 24

pancreatic lipase secreted by ____________

works best where

Answer 24

• pancreatic acinar duct cells

- alkaline environments

Question 25

benefits of pancreatic lipase

Answer 25

- cleaves both sides of glycerol molecule

Question 26

which lipase performs majority of lipolysis

Answer 26

- pancreatic lipase

Question 27

what can inhibit lipases how

Answer 27

- bile acids | - displaces lipase from fatty acid droplets

Question 28

where is colipase secreted

Answer 28

- pancreatic acinar cells

Question 29

purpose of colipase

Answer 29

- binds bile acids and lipase | - stabilizes presence of lipase on surface fat droplets to restore lipolytic activity

Question 30

what is the purpose of micellization

Answer 30

- get the fat droplet into the intestinal epithelial cells

Question 31

what can accumulation of free fatty acids in the intestinal lumen do

Answer 31

- block further lipolysis and digestion

Question 32

what is critical micellar concentration

Answer 32

- concentration of bile salt at which micelle formation occurs

Question 33

composition of micelle

Answer 33

- fatty acids inside | - polar and water soluble surface

Question 34

composition of intestinal brush border

Answer 34

- slightly acidic unstirred water later | - brush border membrane

Question 35

can single fatty acids get through the unstirred water layer

Answer 35

- no

Question 36

purpose of acidity of unstirred water layer

Answer 36

- releases fatty acids from micelles

Question 37

majority of absorption of fatty acids into intestinal bilayer done by how about for larger molecules like cholesterol

Answer 37

- diffusion | - needs membrane proteins

Question 38

are micelles truly required for fat absorption what is their purpose

Answer 38

- no | - increase efficiency

Question 39

purpose of chylomicron formation

Answer 39

- prevent free fatty acids from diffusing back across intestinal epithelium

Question 40

metabolic trapping packages free fatty acids into

Answer 40

- triglyerides - cholesterol esters - phospholipids - fat-soluble vitamins

Question 41

reassembled lipids coated with proteins known as purpose

Answer 41

- apolipoproteins | - chylomicron formation and export

Question 42

resulting chylomicron transported where by what process

Answer 42

- basolateral membrane of enterocyte | - exocytosis

Question 43

can chylomicrons go directly into circulation? where do they enter?

Answer 43

- no. too big | - lacteal within a villus

Question 44

intestinal lacteals drain into the which drains into

Answer 44

- thoracic lymphatic duct | - subclavian veins