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Flashcards in Digestion and Absorption Deck (60)
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1

Digestion of Carbohydrates

salivary and pancreatic amylase

2

Amylase breaks down starches to

maltotriose, Dextrins, Maltose

3

Glycosidases include

maltase, lactase, sucrase, isomaltase

4

Glycosidases are located in

brush border

5

Glycosidases break down saccharides to

glucose, galactose, and fructose

6

Lactase

lactose --> glucose + galactose

7

Sucrase

sucrose --> glucose + fructose

8

GLUT-5

apical and basolateral membrane, transport of fructose

9

SGLT-1

apical membrane, transports glucose and galactose, Na-dependent, Na/K ATPase for gradient

10

GLUT-2

basolateral membrane, transports glucose and galactose

11

Peptide digestion

pepsin, pancreatic proteolytic enzymes, aminopeptidase, cytoplasmic peptidase

12

Pepsin

from chief cells activated by H (pH 1-2)

13

Pancreatic proteolytic enzymes

oligopeptides to amino acids, activated by enterokinase and trypsin (pH 7)

14

Brush border aminopeptidases

hydrolyze remaining oligopeptides, tri- and d-peptides to aa

15

Cytoplasmic peptidases

within enterocytes, try- and di- peptides are broken into AA

16

Pept-1

transports tri- and di-peptides across apical border with H+

17

M-cell Pinocytosis

intact absorption of tri- and di-peptides (bacteria, antibodies)

18

Triglyceride digestion

first broken down into 2-MG and FFA, 2-MG can form micelles

19

Digestion of phospholipids

phospholipase A2 releases FFA and lysophospholipids and long-chain FFA which form micelles

20

Cholesterol and long-chain FFA

form micelles

21

Short-chain and medium-chain FFA

<12 C; do not form micelles

22

Enzymatic cleavage of lipids must occur at

oil-water interface

23

Emulsification

break down of large globules of fat, mastication, retropulsion, peristalsis

24

Gastric Lipase

15% triglycerides to DAG and FFA

25

Colipase

activated by CCK --> trypsin cleavage; binds lipase to the oil-water interface

26

Lipase

inhibited by bile acids, activated by colipase

27

Micelle incorporation

LCFFA, 2-MG, lysophospholipids, cholesterol

28

Will not incorporate into micelle

SCFFA or MCFFA, triglyceride, or bilirubin

29

Absorption of lipid products

micelle break down at apical surface, and contents diffuse

30

SCFFA and MCFFA transport

diffusion