Wk2 Digestion and absorption

Question 1

95% of nutrients absorbed by the time a meal reaches?

Answer 1

distal jejunum

Question 2

Role of plicae circularis and location?

Answer 2

slows food transit in duodenum and jejumun

**not present in ilium

Question 3

Starch/glycogen –> ? –> disaccharides

Answer 3

amylase

Question 4

What protects brush border hydrolases from protease breakdown?

Answer 4

heavy glycosylation

Question 5

Where does does disaccharide –> monosaccharide breakdown occur?

Answer 5

brush border enzymes of duodenum

maltase

sucrase

lactase

Question 6

Where does monosaccharide uptake occur?

Answer 6

duodenum

jejunum

Question 7

how do glucose and galactose get from lumen to intracellular space?

Answer 7

SGLT1

**secondary active transport with Na+ via conc gradient generated by basolateral Na/K ATPase

Question 8

How does fructose get from lumen to intracellular space?

Answer 8

GLUT5

facilitated transporter

Question 9

How do monosaccharides get from intracellular space to the blood?

Answer 9

GLUT2

Question 10

Where/what initiates protein digestion?

Answer 10

pepsin in the stomach

Question 11

Trypsinogen secreted by?

Answer 11

pancreas

Question 12

Amino acid absorption occurs in?

Answer 12

villi in duodenum and jejunum

Question 13

How do AA get across apical membrane?

Answer 13

Na+ sympoters

Question 14

How can di and tri peptides get across apical membrane?

Answer 14

PEPT1

cotransport with H+

Question 15

HOw is the H+ gradient generated to drive PEPT1?

Answer 15

NHE (sodium hydrogen exchanger)

**driven by conc gradient from basolateral Na/K ATPase

Question 16

Mech of passive immunity in forst 6 mo?

Answer 16

intact proteins absorbed by endocytosis

Question 17

Take up proteins which are transferred to lymphocytes as antigens?

Answer 17

M cells

Question 18

Loss of phenylalanine transporter?

Answer 18

Hartnup disease

Question 19

Loss of arginine or cystine transporter?

Answer 19

Cystinuria

Question 20

Gastric lipase secreted by?

Products?

Answer 20

gastric Chief Cells

FA + diglyceride

Question 21

Products of pancreatic lipase?

Answer 21

2 FAs + monoglyceride

Question 22

Triggers release of CCK?

Answer 22

free fatty acids in the duodenum

Question 23

CCK activates release of?

Answer 23

pancreatic lipase

procolipase

Question 24

Colipase job?

Answer 24

recruit lipase to fat droplets

**slide 20

Question 25

Pancreatic lipase inhibited by?

Answer 25

low pH

bile acids

**slide 20

Question 26

capable of hydrolyzing the 2-position fatty acid untouched by lipase:

Answer 26

cholesterol esterase

Question 27

converts cell membranes into FAs and lysophospholipids:

Answer 27

Phopholipase A2

Question 28

Drug: pancreatic lipase inhibitor

Answer 28

Orlistat

Question 29

small bile salt coated cylinder for uptake by epithelial cell

Answer 29

micelle

Question 30

vehicle for fat soluble vitamin uptake?

Answer 30

micelle

Question 31

Lipid entrance into enterocyte

Answer 31

nonionic diffusion

collision with membrane

carrier mediated transport

**slide 25

Question 32

Drug: reduces uptake of cholesterol from lumen

inhibits Niemann Pick C1 Like 1

used to treat hypercholesterolemia

Answer 32

Ezetimibe

Question 33

Where does B-12 (cobalamin) get dropped off by IF?

Answer 33

ilium

Question 34

Why would Zollinger-Ellison syndrome hider lipid digestion?

Answer 34

Increased H+ (decreased pH) inactivates pancreatic lipase

Question 35

Condition causing bile uptake defects in terminal ilium?

Answer 35

Crohn’s

Question 36

Difference between gastric lipase and pancreatic lipase:

Answer 36

GL –> FA + diglyceride

PL –> 2FA’s + monoacylglyceride