Answer :
(a) The two important substances produced by the stomach for digestion are hydrochloric acid (HCl) and pepsinogen.
Hydrochloric Acid (HCl): This is a strong acid that helps break down food in the stomach. It creates an acidic environment, which is necessary for the enzyme pepsin to function. HCl also kills most bacteria and other pathogens ingested with food, thus protecting Veer's stomach from infections.
Pepsinogen: This is an inactive enzyme precursor that is converted into pepsin in the presence of hydrochloric acid. Pepsin is critical for breaking down proteins into smaller peptides, which aids in the digestion process.
(b) Both substances have unique roles in protecting and aiding in digestion:
Hydrochloric Acid (HCl): Apart from its role in digestion, the acidic environment it creates prevents the growth of harmful microorganisms. However, the stomach has a specialized lining, known as the mucosal barrier, which protects it against the corrosive effect of the acid itself.
Pepsinogen (and Pepsin): Pepsinogen itself does not damage the stomach lining because it is initially inactive. It only becomes active in the stomach's acidic environment and starts breaking down protein molecules. The stomach lining's mucous protection guards against any potential damage from the action of pepsin.
(c) When meals are skipped frequently, the stomach continues to produce hydrochloric acid. Without food to digest, the acid can begin to damage the stomach lining over time. This can lead to gastritis or the development of ulcers, which are sores on the stomach lining. The protective mucous layer can be compromised due to continuous exposure to the acid, increasing the risk of damage to the stomach lining.
