Nutrients, Digestion and Absorption

Question 1

What is Lactose ?

Answer 1

glucose + galactose (lactase)

Question 2

What is Sucrose ?

Answer 2

glucose + fructose (sucrase)

Question 3

What is Maltose ?

Answer 3

glucose + glucose (maltase)

Question 4

What border contaisn enzymes for diasach breakdown?

Answer 4

Brush border of mebranes

Question 5

What is the result of unbroken Lactase in SI?

Answer 5

Osmotic drop, diarrhea and LActose INtolerance

Question 6

WHat is Alpha amylose?

Answer 6

glucose linked in straight chains

Question 7

WHat is amylopectin?

Answer 7

glucose chains highly branched

Question 8

What is Cellulose?

Answer 8

Unbranched, linear chains of glucose monomers linked by A-1,4 glycosidic bonds

Question 9

How does Glu enter from lumen to Blood?

Answer 9

Epi cells have SGLT1 transporters, enters epithelium then Glu can go through GLUT-2 transporters and Na is pumped across to allow H2O to follow conc gradient

Question 10

How does Fructose cross epi to blood?

Answer 10

No blood fructose control it is just metabolised directly,

Enters epi via Glut 5 and exits via Glut2

Question 11

What percentage of amino acids are dipeptodes or tripeptides?

Answer 11

66 percent

Question 12

What are Enzymes which hydrolyse peptide bonds and reduce proteins called?

Answer 12

Peptides and proteases

Question 13

What are the two types of peptidases?

Answer 13

Endo and Exco

Question 14

What are the 2 type sof excopeptidases?

Answer 14

Aminopeptidases and carboxypeptidases

Question 15

How does amino acids enter from epi to blood?

Answer 15

SAAT1
allows amino acids and na to cross epi-lumen barrier after which amino acid is transported out and NA/K pump allows na out into blood

Question 16

How do di/tri peptides cross?

Answer 16

PepT1 pumps H ion and Dipeptide in to cell and Dipeptide is excreted out of cell to blood via own spec channe,
H ion pumped back out in exchange for Na which goes through Na/K.

This H creates a microclimate of acidity

Question 17

What form are almost all digested fats in?

Answer 17

triacylglycerol

Question 18

What digests fat in SI?

Answer 18

Pancreatic lipase

Triacylglycerol goes to monoglyceride and 2 fatty acids

Question 19

What does emulsification require?

Answer 19

Mechanical Disruption - caused by smooth muscle contraction

Emulsifying Agents - Prevents re-aggregation e.g Bile salts + Phosopholipids (amiphatic - polar and non polar)

Question 20

What 4 things constitute a micelle?

Answer 20

Bile Salt + Monoglycerides + Fatty Acids + Phospholipids

Question 21

What does a chylomicron contain?

Answer 21

Phospholipid, Cholesterol, and fat soluble vits

Question 22

How do Chylomicrons eneter into blood?

Answer 22

Between Endothelial cells as can not pass through capillaries
Pass through LACTEALS

Question 23

Which vitamins are fat soluble?

Answer 23

ADEK

Question 24

Which are water soluble?

Answer 24

B, C and folic

Question 25

What does vit B12 bind to in the stomach?

Answer 25

Intrinsic factor so can be absorbed in distal ileum

Question 26

What is the result of B12 insfficency?

Answer 26

Pernicious anemia, failure of RBC to mature

Question 27

Which part of the membrane does Iron get transported through and via which transporter into duodenal enteocytes?

Answer 27

Via DMT1 across brush border (H coupled)

Question 28

What complex is iron stored as intracellulary?

Answer 28

Ferritin (protein-iron complex)

Question 29

What membrane does iron cross to get to blood?

Answer 29

serosal membrane

Question 30

what is hyperaemia?

Answer 30

Increased ferritin levels more iron bound in enterocytes

Question 31

What is anemia?

Answer 31

Decreased ferritin, more iron in blood