Exam 4: Lecture 58: Digestion and Absorption of Proteins

Question 1

Which species have a dietary recommendation for the essential amino acids?

Answer 1

Dogs, cats, chickens, pigs, and horses

Question 2

Which species have a dietary protein requirement only?

Answer 2

Cattle, sheep, and goats

Question 3

Why do ruminants not have essential amino acids?

Answer 3

The microbes in the rumen can take dietary protein and make new amino acids

Question 4

What type of enzyme must be present to break down proteins?

Answer 4

Proteases

Question 5

What are endopeptidases?

Answer 5

enzyme that hydrolyzes interior bonds.

Question 6

What are exopeptidases?

Answer 6

enzyme that hydrolyzes exterior bonds

Question 7

Which part of the GIT does protein digestion begin?

Answer 7

Stomach

Question 8

At a low pH, pepsinogen is activated to ______________.

Answer 8

pepsin

Question 9

In young ruminants, the chief cells produce what enzyme that coagulates milk.

Answer 9

Rennin

Question 10

As the digesta enters the SI, what hormone is secreted?

Answer 10

CKK

Question 11

When CKK is released it causes the release of what? (inactive enzymes)

Answer 11

Zymogens

Question 12

Trypsinogen, chymotrypsinogen, proelastase, and procarboxypeptidase A & B are all examples of what?

Answer 12

Zymogens ( inactive enzymes)

Question 13

Which zymogen is the first to be activated?

Answer 13

Trypsinogen

Question 14

What enzyme found on the brush border activates trypsinogen?

Answer 14

enterokinase

Question 15

What is the active form of trypsinogen?

Answer 15

Trypsin

Question 16

The final step in digestion includes what?

Answer 16

Aminopeptidases at the brush border

Question 17

Aminopeptidases break down what substances?

Answer 17

Single amino acids

Question 18

T/F: The enterocyte can only absorb single amino acids.

Answer 18

False - it can absorb amino acids, dipeptides, and tripeptides

Question 19

What type of co-transporters are used for di- and tripeptides?

Answer 19

H+ dependent co-transporters

Question 20

How are amino acids are moved across the basolateral membrane?

Answer 20

Facilitated diffusion

Question 21

If dipeptides and tripeptides are brought into the enterocyte, what enzyme is used to break them down into amino acids to move into the blood?

Answer 21

Peptidase

Question 22

Which enzyme activates trypsinogen to trypsin?
A. Carboxypeptidase
B. Elastase
C. Chymotrypsin
D. Enterokinase

Answer 22

D

Question 23

Prematurely activated enzymes that lead to local damage of exocrine pancreas is usually called what?

Answer 23

Pancreatitis

Question 24

What are some causes of pancreatitis?

Answer 24

Eating a fatty meal, table scraps, eating trash, severe trauma or injury

Question 25

What disease may predispose an animal to pancreatitis?

Answer 25

hyperadrenocorticism (Cushing’s)

Question 26

Chronic pancreatitis has what effect on the pancreatic cells?

Answer 26

Destruction of cells producing enzymes

Question 27

What causes cystinuria?

Answer 27

a defect or absence of an Na+/amino acid co-transporter