Which substance emulsifies fats during digestion?

Which substance emulsifies fats during digestion?

• A. Bile
• B. HCl
• C. Mucus
• D. Amylase

Answer: (A)

Emulsification of fats is the step that creates many small fat droplets so lipases can efficiently break them down. Bile does this in the small intestine. Its bile salts act as detergents with both hydrophobic and hydrophilic parts, coating large fat globules and stabilizing numerous tiny emulsion droplets. This dramatically increases the surface area available for pancreatic lipase to act, making fat digestion possible. Bile is made by the liver and stored in the gallbladder; when fatty chyme reaches the duodenum, hormones trigger the gallbladder to release bile. The bile salts also help form micelles to ferry fatty acids and monoglycerides to the intestinal lining for absorption. In contrast, hydrochloric acid works mainly in the stomach to denature proteins, mucus protects and lubricates the gut, and amylase digests carbohydrates, not fats.

Emulsification of fats is the step that creates many small fat droplets so lipases can efficiently break them down. Bile does this in the small intestine. Its bile salts act as detergents with both hydrophobic and hydrophilic parts, coating large fat globules and stabilizing numerous tiny emulsion droplets. This dramatically increases the surface area available for pancreatic lipase to act, making fat digestion possible. Bile is made by the liver and stored in the gallbladder; when fatty chyme reaches the duodenum, hormones trigger the gallbladder to release bile. The bile salts also help form micelles to ferry fatty acids and monoglycerides to the intestinal lining for absorption. In contrast, hydrochloric acid works mainly in the stomach to denature proteins, mucus protects and lubricates the gut, and amylase digests carbohydrates, not fats.