Describe how bile emulsifies lipids to improve lipase activity.

• A. Bile salts act as a detergent, separating lipid clumps and increasing surface area.
• B. Bile raises temperature.
• C. Bile inhibits lipase.
• D. Bile binds to fatty acids to prevent detection.

Answer: (A)

Bile emulsifies fats to boost lipase efficiency by increasing the surface area available for digestion. Bile salts are amphipathic detergents that coat fat droplets and break them into many tiny droplets. Lipase acts at the oil–water interface, so the more surface area these droplets present, the more triglyceride molecules lipase can access at once, speeding hydrolysis into fatty acids and monoglycerides. This is why the detergent-like action that creates smaller fat droplets best explains improved lipase activity. Temperature changes, lipase inhibition, or binding fatty acids to hide them aren’t how bile works in this context.