Chapter 9: The Digestive System

Question 1

What two enzymes are found in saliva? What do these enzymes do?

Answer 1

• Amylase: Digest starch into smaller sugars (Maltose and Dextrin).
• Lipase: Digest fats

Question 2

Answer 2

Question 3

Answer 3

Question 4

How do bile and pancreatic lipase work together to dihest fats?

Answer 4

bile accomplishes mechanical digestion of fats, emulsifying them and increasing their surface area. Pancreatic lipase accomplishes chemical digestion of fats, breaking their ester bonds.

Question 5

Salivary amylase is also known as ____ or ____.

Answer 5

Ptyalin or Lipase

Question 6

Food is prevented from entering the larynx during swallowing by the ____.

Answer 6

Epiglotis

Question 7

The chemical digestion of carbohydrates occurs in both the mouth and small intestine, with the two amylases targeting complementary starches. Salivary amylase (active in the mouth) has a higher specificity for ____, while pancreatic amylase (active in the small intestine) has a higher specifity for____.

Answer 7

1. Rapidly-soluble starches
2. less soluble, more nonpolar starches

Question 8

The rhythmic contraction of smooth muscle that propels food toward the stomach is called ____.

Answer 8

Peristalsis

Question 9

The 6 products that the stomach secretes and their functions.

Answer 9

1. HCl
   
   1. Kills microbes, denatures proteins, and converts pepsinogen into pepsin.
2. Pepsinogen
   
   1. Cleaved in the stomach to pepsin; an enzyme that partially digest proteins.
3. Mucus
   
   1. Protects Mucosa
4. Bicarbonate (HCO3-)
   
   1. Protects Mucosa
5. Water
   
   1. dissolves and dilutes ingested material
6. intrinsic factor
   
   1. required for normal absorption of vitamin B12

Question 10

The small intestine consists of three segments which are

Answer 10

1. Duodenim
2. Jejunum
3. Ileum