Which tube confirms that there is no lipase in bile salts or vegetable oil?

• A. Tube 2
• B. Tube 3
• C. Tube 1
• D. Tube 4

Answer: (D)

Lipase is the enzyme that hydrolyzes triglycerides in fats like vegetable oil into fatty acids and glycerol. Bile salts help by emulsifying the fat, increasing the surface area for lipase, but they don’t hydrolyze fat themselves. In the tube that has bile salts and vegetable oil but no lipase, there’s no enzyme to catalyze the breakdown, so no fatty acids are produced and the pH indicator remains the same color. That lack of change shows there is no lipase present in that setup. Tubes that do contain lipase would show hydrolysis and a color change due to fatty acid production, while tubes without fat substrate wouldn’t demonstrate lipase activity for reasons unrelated to enzyme presence.