Question

Assertion
The liver secretes bile juice that does not contain enzymes but helps in digestion
Reason
Bile carries out emulsification of fats and provides an alkaline medium for the activity of other enzymes
A. Both Assertion and Reason are correct and Reason is the correct explanation of Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
C. The assertion is correct but Reason is incorrect
D. Both Assertion and Reason are incorrect

Answer 1

Hint: Bile juice has certain pigments that help in breaking the complex fat molecules into the small molecules and helps in its digestion.

Complete answer:
The liver secretes bile juice dark green to the brownish colored fluid that helps in the digestion of fat or lipid molecules but it does not secrete any enzymes for digestion. Bile is secreted by the liver but it is stored in the gallbladder which after eating food will be stored later in the duodenum of the small intestine.
Bile consists of around 97-98% water, 0.7% bile salts, 0.2% bilirubin, 0.51% fats which may be cholesterol, fatty acids, and lecithin, and a small number of inorganic salts. Bilirubin (orange-yellow), and biliverdin (green) are the two main pigments of bile. The biliverdin is an oxidized form of bilirubin. These two pigments are responsible for the brown color of the semi-solid feces.
In normal human adults, around 400-800 milliliters of bile are produced every day. They help in emulsifying fats present in the food. The bile salts form micelles where the pancreatic enzyme acts upon it and breaks the fat molecules into smaller molecules. This helps in the absorption of fats like vitamins A, K, and E. The pH of the bile is around 7.5-8.05 which is higher than the bile in the gallbladder. Bile is generally alkaline.
So, the correct answer is ‘Both Assertion and Reason are correct and Reason is the correct explanation of Assertion’.

Note: Bile was first discovered in 1848. In 1912, a German chemist Heinrich Otto Weiland revealed the structure of bile juices and later in 1927 won the Nobel Prize for chemistry. He separated three bile acids and stated that they have similar structures and were related to cholesterol.