Lecture 58

Question 1

T/F: Some domestic species have a dietary requirement for essential amino acids (ex. Dogs, cats, chickens, pigs & horses)

Answer 1

T

Question 2

T/F: Some domestic species have a dietary rprotein requirement only (Cattle, sheep, goats, & ruminants)

Answer 2

T

Question 3

Why do only some species have a dietary protein requirement & not a dietary requirement for essential amino acids

Answer 3

Because the microbes in the rumen can take dietary protein & make essential Aas that the animal can absorb

Question 4

Proteins must be digested to absorbable forms like _____ & _____ via enzymes called _______

Answer 4

AAs, short peptides, protease

Question 5

How is digestion of proteins ultimately completed in the stomach

Answer 5

By endopeptidases (hydrolyzes the interior bonds) & exopeptidases (hydrolyze the exterior bonds)

Question 6

What are the steps of protein digestion in the stomach

Answer 6

Pepsinogen is activated into pepsin @ low pHs (endopeptidase)
HCl causes the proteins to unfold & expose peptide bonds to pepsin
Large peptide fragments & some free AAs are generated

Question 7

What is different about the digestion of proteins in young ruminants

Answer 7

They have chief cells that produce rennin

Question 8

Definition: “An enzyme that coagulates milk to decrease the passage rate”

Answer 8

Rennin

Question 9

What is used in the SI for the digestion of proteins

Answer 9

Pacreatic & brush border proteases

Question 10

What are the steps of protein digestion in the SI

Answer 10

Digest enters the SI & CCK is released
This causes a release of zymogens (inactive enzymes) like trypsinogen
Trypsinogen is activated by enterokinase to form trypsin
Trypsin then activates other zymogens

Question 11

Which zymogens are endopeptidases

Answer 11

Trypsin
Chymotrypsin
Elastase

Question 12

Which zymogens are exopeptidases

Answer 12

Carboxypeptidases A & B

Question 13

What is the final step of protein digestion in the SI

Answer 13

Aminopeptidases on the brush border breaks down the Aas

Question 14

T/F: ONLY Aas are absorbed into the blood

Answer 14

T

Question 15

What can enterocytes absorb

Answer 15

Amino acids
dipeptides
Tripeptides

Question 16

What are the co transporters in the luminal membrane for Aas

Answer 16

Use the Na gradient
neutral
acidic
basic
imino [proline] AAs

Question 17

How are di & tri peptides transported

Answer 17

Through H+ dependent cotransport
uses a H+ gradient
Peptides are cleaved to AAs inside the cell by aminopeptidase

Question 18

How do amino acids move across the basolateral membrane

Answer 18

Facilitated diffusion

Question 19

Definition: “Insufficient production & secretion of digestive enzymes, can be caused by chronic pancreatitis.”

Answer 19

Exocrine pancreatic insufficiency

Question 20

Definition: “can be idiopathic, because of hyperadrenocorticism (an increase in steroids which leads to an increase in glucose & circulating triglycerids), or a deficiency of pancreatic enzymes & fluid in intitial stages”

Answer 20

Acute or chronic pancreatitis

Question 21

Definition: “Defect or absence of an Na/ Amino Acid co transporter (specifically cysteine, lysine, arginine, & ornithine), and can contribute to crystal formation & calculi”

Answer 21

Cystinuria