Chapter 14: Digestion

Question 1

The pancreas releases ___________ to buffer the pH of the stomach juices.

Answer 1

NaHCO3

Question 2

Pepsin requires ____________ to become active.

Answer 2

1. zymogen activation
2. low pH
3. partial denaturation of protein

Question 3

Complex carbohydrates are absorbed:

Answer 3

as they are converted to glucose and simple sugars.

Question 4

Glucose transport takes place by:

Answer 4

secondary active transport using the sodium glucose cotransporter.

Question 5

Snake venom’s poison is actually:

Answer 5

a collection of digestive enzymes.

Question 6

The transport of lipids in the lymph is carried out by:

Answer 6

chylomicrons

Question 7

Define: Digestion

Answer 7

The conversion of food into simple biochemicals

Question 8

Define: Cholecystokinin

Answer 8

Results in the secretion of digestion enzymes

Question 9

Define: Zymogens

Answer 9

Proenzymes

Question 10

Define: Enteropeptidase

Answer 10

Activates trypsin

Question 11

Define: (alpha)-Amylase

Answer 11

Digests carbohydrates

Question 12

Define: Emulsion

Answer 12

Water-lipid droplets

Question 13

Define: Bile Salts

Answer 13

Inserts into emulsions to facilitate lipase action

Question 14

Define: Chylomicron

Answer 14

Transports dietary lipids from intestinal cells to elsewhere in the body

Question 15

Define: K+/H+ ATPase

Answer 15

Acidifies the stomach

Question 16

Define: Lipase

Answer 16

Hydrolyzes lipids

Question 17

What properties of lipids make their digestion more complicated than that of carbohydrates and proteins?

How are lipids made accessible for digestion?

Answer 17

Unlike proteins and carbohydrates, neither lipids nor the products of lipid digestion - fatty acids- are water soluble. The lipids are converted into mixtures of lipid droplets and water (emulsions), a conversion enhanced by bile salts.

The emulsions are accessible to lipases. The fatty acids generated by the lipases are carred in micelles to the intestinal membrane.

Question 18

Why are most digestive enzymes produced as zymogens?

Answer 18

Secretion of the digestive enzymes as precursors reduces the likelihood that the secretory tissue will be damaged by its secretory products.