National League for Nursing (NLN) Science Practice Exam

What role does bile play in digestion?

1. Regulates blood sugar

2. Breaks down proteins

3. Emulsifies fats

4. Absorbs nutrients

The correct answer is: Emulsifies fats

Bile plays a crucial role in the digestion of fats, primarily through the process of emulsification. When fats are consumed, they tend to clump together and form large globules, which makes it difficult for digestive enzymes to act on them effectively. Bile, which is produced by the liver and stored in the gallbladder, contains bile salts that have both hydrophilic (water-attracting) and hydrophobic (water-repelling) properties. When bile is released into the small intestine, it surrounds the fat droplets, breaking them into smaller particles, thus increasing the surface area available for enzymes like lipase to act upon. This emulsification process is essential for the efficient digestion and absorption of dietary fats. The other roles mentioned in the options, such as regulating blood sugar and breaking down proteins, are not functions of bile. Bile does not directly absorb nutrients either; that function is primarily carried out by the small intestine lining after emulsification has occurred, making the selected choice correct in describing bile's specific and vital function in the digestive process.