Which statement correctly describes the role of bile in fat digestion?

Which statement correctly describes the role of bile in fat digestion?

• A. Breaks down lipids into glycerol only
• B. Is unnecessary for fat digestion
• C. Emulsifies fats to form micelles allowing lipase activity
• D. Neutralizes fatty acids

Answer: (C)

Bile’s job in fat digestion is to make fats accessible to the enzymes and to help move the digestion products into the intestinal lining. Bile salts are amphipathic, so they surround fat droplets and break them into much smaller pieces. This emulsification greatly increases the surface area for pancreatic lipase to act, letting the enzyme more efficiently hydrolyze triglycerides into fatty acids and monoglycerides. After lipase does its work, the fatty acids and monoglycerides are not very water-soluble, so bile salts form micelles with these products to keep them solubilized and readily delivered to the intestinal mucosa for absorption. That combination of emulsifying fats and forming micelles to shuttle digestion products to the surface makes the described statement the best one. The other options miss the essential roles: bile does not break fats down into glycerol only, it is not unnecessary for fat digestion, and its main job is not neutralizing fatty acids.

Bile’s job in fat digestion is to make fats accessible to the enzymes and to help move the digestion products into the intestinal lining. Bile salts are amphipathic, so they surround fat droplets and break them into much smaller pieces. This emulsification greatly increases the surface area for pancreatic lipase to act, letting the enzyme more efficiently hydrolyze triglycerides into fatty acids and monoglycerides. After lipase does its work, the fatty acids and monoglycerides are not very water-soluble, so bile salts form micelles with these products to keep them solubilized and readily delivered to the intestinal mucosa for absorption. That combination of emulsifying fats and forming micelles to shuttle digestion products to the surface makes the described statement the best one. The other options miss the essential roles: bile does not break fats down into glycerol only, it is not unnecessary for fat digestion, and its main job is not neutralizing fatty acids.