Intestinal Digestion and Absorption Prunuske

Question 1

How do monosaccharides get absorbed?

Answer 1

SGLT-1

Question 2

How do peptides get absorbed?

Answer 2

PEPT-1 via H+

Question 3

Hartnup disease

Answer 3

Defect in L-phenylalanine transporter

but you can still get phenylalanine via peptide transporter

Question 4

Cystinuria

Answer 4

Defect in L-arginine or cystine transporter

Question 5

Besides peptides, what else is taken up by PEPT-1?

Answer 5

DRUGS! Like Cephalosporin

Question 6

Sucrose

Answer 6

Glucose + Fructose

Question 7

Maltose

Answer 7

Glucose + Glucose

Question 8

Lactose

Answer 8

Glucose + Galactose

Question 9

Fructose transporter

Answer 9

GLUT5

Question 10

How do amino acids get absorbed?

Answer 10

Via Na+ dependent symporters

Question 11

How are all monosaccharides getting into the blood?

Answer 11

GLUT2 on basolateral membrane

Question 12

What does trypsinogen need to become active?

Where does trypsinogen come from?

Answer 12

Enteropeptidase! From brush border

Trypsinogen comes from pancreas

Question 13

90 % of dietary lipids are what?

Answer 13

TG

Question 14

Chief cells secrete what 2 things?

Answer 14

lipase and pepsin

Question 15

Free FA in the duodenum triggers release of what?

Answer 15

CCK

Question 16

What does CCK do?

Answer 16

Activates pancreatic acinar secretion of lipase & procolipase

Question 17

How do bile acids affect lipase?

Answer 17

They inhibit lipase binding to fat droplets

Question 18

Does low or high pH inhibit pancreatic lipase?

Answer 18

Low (no food at low pH)

Question 19

What activates colipase?

Answer 19

Trypsin

Question 20

What does Colipase do?

Answer 20

It binds bile acids so lipase can cleave fatty acids

Question 21

So what is critical for lipase’s activity in the presence of bile?!

Answer 21

Colipase!

Question 22

Why are some of the other fat digesting enzymes of the pancreas activated once they reach the duodenum?

Answer 22

Higher levels of Ca++ in duodenum

Question 23

How must fat soluble vitamins be taken up?

Answer 23

In MICELLES

Question 24

How do lipids enter enterocytes? 3 ways

Answer 24

Nonionic diffusion
Collision with membrane
Carrier mediated transport

Question 25

How does Ezetimibe work?

Answer 25

Reduces uptake of cholesterol by inhibiting Niemann-Pick C1 Like 1

Question 26

What happens to most absorbed FA in enterocytes?

Answer 26

Put into chylomicrons

Question 27

What drug can interfere with Vitamin B12 absorption?

Answer 27

Metformin

Question 28

If a patient has a colipase or lipase deficiency, what will they have?

Answer 28

Chronic pancreatitis

Question 29

What pancreatic enzyme is inactivated due to Zollinger-Ellison Syndrome?

Answer 29

Lipase! Super sensitive to low pH

Question 30

Abetalipoproteinemia

Answer 30

Abnormal chylomicron formation

Question 31

IN what disease is there inadequate uptake up bile salts?

Answer 31

Crohn Disease

Question 32

How does dumping syndrome affect fat digestion?

Answer 32

Inadequate time for fat digestion/absorption so it is decreased