Video Transcript
What is the primary purpose of bile
in digestion? (A) To catalyze the hydrolysis of
carbohydrates, (B) to emulsify fats, (C) to activate trypsinogen, or (D) to break
down proteins.
Our question involves
digestion. So let’s start by taking a look at
the major organs of the digestive system. They include the mouth, esophagus,
stomach, and small and large intestines, as well as the liver, gallbladder, and
pancreas, which are accessory organs of the digestive system.
Food does not directly pass through
the accessory organs, yet they all play a critical role in digestion. For example, the liver has the
important job of producing bile. This substance is stored in the
gallbladder before being secreted through the bile duct into the duodenum. The main function of bile is to
break down lipids into smaller droplets, a process known as emulsification. The result of emulsification is
that a larger surface area of lipids is exposed to lipases, the enzymes that digest
fat in the small intestine. This increases the efficiency of
lipid hydrolysis.
Bile is an alkaline substance. So it has the secondary function of
neutralizing excess stomach acid before it enters the small intestine.
We now have enough information to
identify answer choice (B) as the correct answer. The primary purpose of bile in
digestion is to emulsify fats.
