Digestion & Absorption I & II

Question 1

In addition to providing amino acids, what other function does proteins serve?

Answer 1

delivers the dietary essential amino acids which cannot be synthesized in humans

Question 2

What does linoleic acid produce?

Answer 2

arachidonic acid

Question 3

what does alpha linoleic acid produce?

Answer 3

DHA

Question 4

What is the intrinsic factor formed in the parietal cells of the stomach needed for?

Answer 4

uptake of B12 into the mucosal cells

Question 5

what is released by parietal cells?

Answer 5

gastric acid (HCL) 
G cells release gastrin which releases gastric acid by parietal cells

Question 6

what do chief cells release?

Answer 6

pepsinogen and gastric lipase

Question 7

primary bile acids - where are they formed

Answer 7

only formed in liver - the liver uses free cholesterol

Question 8

secondary bile acid - where are they formed

Answer 8

from primary bile acids and by intestinal bacteria

Question 9

where are primary and secondary bile acids conjugated?

Answer 9

ONLY in the liver

Question 10

what does the liver release into bile?

Answer 10

conjugated bile salts, phosphatidylcholine, free cholesterol and conjugated bilirubin

Question 11

what role does albumin play? (2)

Answer 11

needed for osmolatity and used in blood to transport protein

Question 12

what do individuals with gout have?

Answer 12

have high uric acid levels in blood

Question 13

what should individuals with gout eat?

Answer 13

diet low in purine bases

Question 14

how do fat soluble vitamins (ADEK) and dietary essential fatty acids reach the liver?

Answer 14

chylomicron remnants

Question 15

how do medium chain FA reach the liver?

Answer 15

released from intestinal mucosal cells directly as

free fatty acids into the portal vein and reach the liver.

Question 16

what nutrient is rich in medium chain FA?

Answer 16

Medium-chain fatty acids are found in TAGs of milk and this food source allows the rapid uptake into the liver for energy metabolism.

Also, TAGs with medium-chain fatty acids can be degraded by lingual and gastric lipase which do not need bile salts for activity.

Question 17

why are conjugated bile salts important?

Answer 17

Bile salts are needed for lipid digestion for the action of pancreatic lipase and of pancreatic phospholipase A2.

Last but not least, bile salts are also needed for the uptake of the digested lipids into intestinal mucosal cells.

Question 18

what do gastic lipase and lingual lipase work on at low pH?

Answer 18

Lingual lipase and gastric lipase act mainly on TAGs with medium-chain fatty acids, as found in milk.

Question 19

what is an endopeptidase? (like pepsin)

Answer 19

which means that it cleaves proteins from the inside and leads to smaller proteins and peptides.

Question 20

What does secretin do? (2 things)

Answer 20

Secretin leads to the release of bicarbonate and water from the pancreas.

It also inhibits to a certain degree the release of chyme from the stomach which allows time for neutralization of the present chyme so that the food can be further digested by pancreatic enzymes which need a more neutral pH.

Question 21

what are CCK main functions?

Answer 21

CCK inhibits gastric motility and production of gastric acid.

CCK also leads to the release of pancreatic enzymes and activation of enteropeptidase which can activate released trypsinogen, but only in the lumen of the duodenum. Water is also released by the pancreas.

Question 22

what are the specific injury markers of pancreatitis?

Answer 22

pancreatic α-amylase and
pancreatic lipase in the blood.

Often this is due to ethanol abuse, gallstones or very
high levels of VLDL in the blood (hypertriacylglyerolemia). It is also found in
patients with cystic fibrosis

Question 23

What does pancreatic lipase need to cleave TAGs?

Answer 23

colipase and bile salts

Question 24

what are the four amino acid inactive proteases in pancreas?

Answer 24

trypsinogen, chymotrypsinogen, proelastase, and two procarboxypeptidases

Question 25

name the two fat proteases from pancreas?

Answer 25

procolipase and prophospholipase A2