Section 7: Digestion and Absorption of Carbohydrates and Protein

Question 1

Which complex molecules can be absorbed directly across the epithelium

Answer 1

none, not through cell membranes or tight junctions

Question 2

Enzyme locations for digestion and absotption of carbohydrates:

Answer 2

brush border and lumen

Question 3

Final acts of digestion enzymes are here:

Answer 3

brush border

Question 4

Which glucose bonds are harder to break?

Answer 4

1,6

Question 5

Enzyme in carbohydrates breakdown:

Answer 5

alpha amylase of pancreas, alpha dextrinase and glucoamylase

Question 6

Fructose + Glucose:

Answer 6

sucrose

Question 7

2 transport proteins;

Answer 7

glucose carrier and fructose carrier

Question 8

test of carrier mediated transport:

Answer 8

transported against concentration gradient, tube in rabbits stomach, infuse bolus of glucose solution, lumen of stomach now has high glucose concentration, glucose concentration higher in lumen than blood, no glucose after 90 minutes. Below dotted line = active transport

Question 9

Glucose sugar levels:

Answer 9

90 mg percent (90 mMol)

Question 10

What sugar will be absorbed preferentially over glucose?

Answer 10

galactose

Question 11

Can provent functions of glucose carrier required for absorption:

Answer 11

oubain (poison), depeds on metabolic enegy, lumen Na+ depeneded

Question 12

Glucose and galactose on this protien:

Answer 12

SGLT

Question 13

What is SGTL:

Answer 13

cotransporter, one is not transported without the other

Question 14

Glucose is moved out on the basolateral side via this:

Answer 14

GLUT 2

Question 15

Ouabiain blocks:

Answer 15

the Na/K pump, Na increases in the cell, prevents glucose transport

Question 16

True or False? Transport of glucose is concentration dependent.

Answer 16

F

Question 17

fructose transport

Answer 17

can’t go against a concentration gradient, can’t be poisoned by oubain, no ATP involved, no sodium involved, ,

Question 18

Which basolateral transporter moves fructose out of the cll?

Answer 18

GLUT 2, facilitated diffusion

Question 19

True or False? lactose intolerabitliy leads to a decreases in luminal osmolarity.

Answer 19

F. increase

Question 20

True or False? Fluid accumulates in the lumen of the stomach in people with lactose intolerance.

Answer 20

T

Question 21

What are the more immediate issues that lead to diarrhea for lactose intolerant people?

Answer 21

luminal distension and enhanced peristalsis

Question 22

Where do bacteria attack lactose in the gut?

Answer 22

small and large intestines

Question 23

Liters of water entering the intestines each day:

Answer 23

8-10L (check)

Question 24

True or False? High fructose corn syrup is worse for you than sugar.

Answer 24

F

Question 25

Sugar is high in __ and low in ___:

Answer 25

calories, nutriiton

Question 26

Dietary fibers:

Answer 26

cellulose, hemicelluose, or pectins

Question 27

These enzymes don't absorb cellulose, hemicelluose, or pectins

Answer 27

pancreatic or brush border enzymes

Question 28

Organic anions of dietary fiber are:

Answer 28

osmoticaly active, less likely to be constipated

Question 29

Bacteria break fibers dow to:

Answer 29

short chain fatty acids, H2, CO2, and methane

Question 30

Short chain fatty acids that fiber is broken down to:

Answer 30

acetate, propionate, butyrate

Question 31

True or False? None of the short chain fatty acids that are produced by the break down of fibers are absorbed.

Answer 31

F. Some are

Question 32

Toxins produced by bacteria can cause:

Answer 32

secretory diarrhea

Question 33

Protiens in the lumen:

Answer 33

125gm/day or 20% of the diet in U.S.

Question 34

Amount of protein enzymes in the lumen per day:

Answer 34

30 mg/ day

Question 35

This makes up 25 mg/day of the protein in the lumen:

Answer 35

dead epithelial cells

Question 36

Turnover rate of epithelial cells in the lumen:

Answer 36

5 days

Question 37

5 carriers in the proximal intestines:

Answer 37

Neutral AA's, Basic AAs, Acidic AAs, Imido AA, Di- and tri-peptides

Question 38

First real protease:

Answer 38

pepsin

Question 39

What enzyme does most of the work of breaking proteins down?

Answer 39

pancreatic protease

Question 40

Enzymes involved in protein digestion:

Answer 40

pancreatic protease and pepsin

Question 41

Bile acids, and water soluble amino acids are returned via:

Answer 41

hepatic portal vein

Question 42

What peptidases break down the smaller peptides?

Answer 42

intracellular

Question 43

Characteristics of amino acids absorption:

Answer 43

transport aginst a concentration gradient, competition between amino acids, poisoned by ouabia (Na is involved), depends on metabolic energy to be absorbed, depend on luminal sodium

Question 44

Amino acids absorption in the duodenum and jejunum:

Answer 44

Na coupled, proved by polarizing epithelial cells, Na/K pump always on the basolateral side

Question 45

True or False? Amino acids acid absorption is always transported via this type of transport:

Answer 45

secondary active transport

Question 46

Vitamin B12 is aka:

Answer 46

Cobalamin

Question 47

Vitamin B12 is needed for:

Answer 47

making rbc

Question 48

only thing the stomach does that is required for living

Answer 48

intrinsic factor secreted by parietal cells to absorb B12 in the blood

Question 49

How is CBL broken down in the stomach

Answer 49

pepsin and the acidity of the stomach

Question 50

Vitamin:

Answer 50

essential to live, you can't make yourself

Question 51

What cells secrete intrinsic factor?

Answer 51

parietal cells

Question 52

What is secreted by gastric glands which then binds to cobalmin

Answer 52

Haptocorrin,

Question 53

What is required for the absorption of B12?

Answer 53

intrinsic factor

Question 54

Pernicious anemia:

Answer 54

large, odd red blood cells that get stuck in the capillaries, feed raw liver, they get better

Question 55

When is CBL released into the small intestines?

Answer 55

proteolyic degradation of haptocorin

Question 56

Why did the liver make the patients better?

Answer 56

store of B12 in the liver

Question 57

What are absorbed in the jejunum?

Answer 57

Trigycerides, fat soluble vitamins, cholesterol, and lecithin

Question 58

When is most absorption done?

Answer 58

mid jejunum

Question 59

Why are fats harder to digest?

Answer 59

not water soluble

Question 60

Reabsorbed in the ileum:

Answer 60

bile salts and V12

Question 61

What sugars make up the largest and smallest components of our diet?

Answer 61

sucrose (30%) and lactose (6%)