How does hydrochloric acid help in facilitating the action of pepsin?

The correct answer is Hydrochloric acid creates an acidic medium which facilitates the action of the enzyme pepsin.

Key Points

• The glands of the stomach are called gastric glands.
• Gastric glands secrete hydrochloric acid, a protein digestive enzyme called pepsin.
• Hydrochloric acid helps in the breakdown, digestion, and absorption of nutrients such as protein. It also kills germs and viruses in the stomach, keeping your body state from infection.
• Without adequate HCI secretion, larger fragments of proteins enter the small intestine and may compromise the efficacy of digestive processes.
• HCI provides an acidic pH of 1.8 optimal for pepsin.
• HCI activates pepsinogen into the enzyme pepsin which helps digestion by breaking the bonds linking amino acids. This process is known as Proteolysis. 
• Pepsin is produced by the cells that are present in the stomach lining.
  • It is a very important enzyme as it breaks down the complex proteins found in daily food into smaller peptides.
  • Pepsin works best in an acidic condition which is why the stomach also produces acid to help break down proteins.

Additional Information

• Gastric glands also secrete Renin which helps to break down the caseinogen into Casein found in milk.
• As soon as the food reaches the duodenum bile juice from the lever combines with it. Bile juice is alkaline and it turns the acidic medium of food into alkaline.
• Pancreas also secretes three types of juices that help in digestion.
  • Trypsin - It converts the protein and peptone into polypeptides and amino
  • Analyse - It converts the starch into double sugar.
  • Lipase - It converts emulsified fats into glycerol and fatty acids.