Gi Absorption Proteins & Carbs

Front 1

types of proteins that can be absorbed in SI

Back 1

di, tri & tetra peptides
aa's

Front 2

where does protein digestion begin

Back 2

in duodenum with enteropeptidase conversion of trypsinogen to trypsin

Front 3

pancreatic peptidases

Back 3

trypsin
chymotrypsin
elastase
carboxypeptidase A & B

Front 4

activation of trypsin

Back 4

secreted by pancreas as trypsinogen
activated by enteropeptidase on brush border

Front 5

characteristics of enteropeptidase

Back 5

membrane bound
on brush border of SI
serine protease (NOT kinase)

Front 6

"layers" of peptidases

Back 6

1st layer
trypsin
chymotrypsin
elastase
carboxypeptidase A & B
2nd layer in cytoplasm
"cytoplasmic peptidase"

Front 7

digestion of proteins

Back 7

begins in small intestine
trypsinogen activated by enteropeptidase
trypsin activates other peptidases
cut into di, tri & tetras
transported into cytoplasm
cytoplasmic peptidase
specific aa transporters at basolateral membrane

Front 8

peptide transporter into enterocyte

Back 8

Na/K pump at bl memb drives Na out
draws Na in at apical aa's cotransport
PepT1- peptides & H+ in

Front 9

inability to absorb neutral aa's from SI lumen
(need tryptophan to make niacin so get niacin def)
symptoms include dermatitis exacerbated by sunlight

Back 9

Hartnup disease

Front 10

aa transporter with 2 subunits

impaired cationic aa transporter
liver & kidney problems
sx of malnutrition

Back 10

cystein (def is cysteinuria)

Front 11

maple syrup urine disease

Back 11

leucin, isoleucine, valine

Front 12

absorption of carbohydrates

Back 12

begins in mouth with alpha amylase (amylose, amylopectin)
hydrolyzed to monosaccharides
SGLT 1 brings glucose & galactose in from lumen
GLUT 5 brings in fructose
transported out of enterocyte by GLUT 2

Front 13

maltose

Back 13

2 glucose (alpha 1-4 link)

Front 14

maltotriose

Back 14

3 glucose (alpha 1-4 links)

Front 15

alpha dextrins

Back 15

short oligosaccharides

Front 16

lactose

Back 16

glucose & galactose

Front 17

sucrose

Back 17

glucose & fructose

Front 18

trehalose

Back 18

glucose

Front 19

SGLT 1 transporter

Back 19

Na/K pump at BL membrane (Na out)
SGLT at apex
glucose or galactose and 2 Na come in

Front 20

GLUT 5 transporter

Back 20

fructose in
facilitated diffusion

Front 21

protein disorders

Back 21

Cysteinuria/lysinuria
Maple Syrup Disease
Hartnup disease

Front 22

Carbohydrate disorders

Back 22

GGM
Sucrase Isomaltase Deficiency
Lactase deficiency
Hypolactasia
Celiac Sprue

Front 23

severe watery diarrhea in infant
resolved if on fructose diet

Back 23

GGM- glucose/galactose malabsorption
mutation in gene encoding SGLT 1

Front 24

characteristics of SGLT 1 transporter

Back 24

14 membrane spanning domains
Glycoprotein (subjected to post transcriptional modification- glycosylation activates or inactivates)

Front 25

Severe watery diarrhea at about 3 months
resolved with galactose only

Back 25

Sucrase/Isomaltase Deficiency
(glucose & fructose not absorbed)

Front 26

diarrhea
releived with removal of lactose

Back 26

lactase deficiency

Front 27

hypolactasia

Back 27

lactose intolerance
starts around 2-5 years
recent mutation allows N Europeans to drink milk

Front 28

detection of lactose intolerance

Back 28

lactose tolerance test
stool acidity test
Breath hydrogen test

Front 29

flattening of lining of SI
poor absorption of nutrients

Back 29

Celiac Sprue
autoimmune rxn to gluten
1/133 in US

Front 30

mechanism of diarrhea in carb absorption dz

Back 30

osmotic
b/c Na & H2O not able to come in