Essentials of Anatomy and Physiology

374 The Digestive System

Table 16–1 THE PROCESS OF DIGESTION

Enzyme or Organ Other Secretion Function Site of Action Salivary glands Stomach

Liver Pancreas

Small intestine

Amylase

Sucrase, Maltase, Lactase

Lipase

Bile

Pepsin

Trypsin

Peptidases

Proteins

Fats

Salivary Carbohydrates glands

Liver

Stomach

Pancreas

Small intestine

Amylase Pepsin HCI

Bile salts Amylase Trypsin Lipase Peptidases Sucrase Maltase Lactase

Converts starch to maltose

Converts proteins to polypeptides

Changes pepsinogen to pepsin; maintains pH
1–2; destroys pathogens

Emulsify fats

Converts starch to maltose

Converts polypeptides to peptides

Converts emulsified fats to fatty acids and glycerol

Convert peptides to amino acids

Converts sucrose to glucose and fructose

Converts maltose to glucose (2)

Converts lactose to glucose and galactose

Oral cavity Stomach Stomach

Small intestine Small intestine Small intestine Small intestine Small intestine Small intestine Small intestine Small intestine

Table Figure 16–A Functions of digestive secretions. QUESTION:Proteins are digested by secretions from which organs? How did you decide?