Which of the following statements about bile in the digestive system are correct?
- It emulsifies fat globules.
- It dilutes the contents of the small intestine.
- It lowers the activation energy of lipase.
- It helps to reduce the acidity of the contents leaving the stomach.
A. 1, 2 and 3 only
B. 1, 2 and 4 only
C. 1 and 2 only
D. 2 and 3 only
E. 1 and 4 only
The correct answer is B.
What is bile ?
Bile is produced by the liver and then stored into the gallbladder for later use.
It goes from the liver, down the hepatic duct and the cystic and finally, to the gallbladder, which is a little pouch under the liver.
The gallbladder is NOT necessary for digestion : in fact, it is entirely possible to live without one. The liver produces enough bile to digest the food that you’ve ingested and instead of being put away, it will just continue flowing down the digestive tracts.
What is it for ?
Its main purpose is to ensure the the emulsification of fats into smaller droplets during digestion and to carry away the waste (like hemoglobin from destroyed red blood cells and excess cholesterol).
Bile is a good solvent and therefore, dilutes the contents of the small intestine.
This emulsification increases the area that lipases can work on : it does NOT lower its activation energy but only facilitates its activity.
Bile is also important for role the neutralization of hydrochloric acid (HCl) that comes from the stomach into the intestine due to the fact that it is an important source of alkali.
Actually I thought the alkali juices come from pancreas? Bicarbonate produced by pancreas and helps to reduce acidity of HCl from stomach.
Is bile reduce the acidity too?
And I thought bile salt can activate the lipase but not bile itself. Is it correct?