Emulsification of fat is carried out by

(a) Bile pigments

(b) Bile salts

(c) HCl

(d) Pancreatic juice

The digestion and absorption of lipids is a vital function supported by the liver through the secretion of bile. Bile acts as a surfactant, breaking large fat globules into smaller droplets (emulsification).

Bile salts are amphipathic molecules with a hydrophilic side and a hydrophobic side. They surround fat droplets to form micelles, orienting their hydrophobic sides inward (towards fat) and hydrophilic sides outward. This arrangement prevents fat droplets from recombining into larger particles.

By dispersing fats into micelles, bile salts increase the surface area for the enzyme pancreatic lipase, significantly aiding lipid digestion and absorption.

Additional Information

• Bile is a bitter-tasting, dark green to yellowish-brown fluid. It is produced in the liver, stored in the gallbladder, and released into the duodenum after eating.
• Functions of bile:
  • Acts as an emulsifying agent in fat digestion.
  • Helps in the excretion of cholesterol and bile pigments (from hemoglobin breakdown).

Composition of Bile Juice:

• Water
• Bile salts (e.g., cholic, chenodeoxycholic, deoxycholic, lithocholic acid)
• Mucus
• Pigments (e.g., bilirubin glucuronide)
• Fats (phospholipids, cholesterol)
• Organic salts

Correct Answer: Bile salts