The three tenets to the cell theory are as described below: All living organisms are composed of one or more cells. (However, this is considered a controversy because non-cellular life such as viruses are disputed as a life form. See Non-cellular life.)
Hydrochloric acid is the primary digestive acid and has several roles in digestion. The acid prevents harmful bacteria from entering your system by sterilizing it. Another function of hydrochloric acid is to trigger the release of pepsin. You need hydrochloric acid to absorb minerals like magnesium, sodium and iron. Gastric acid is so strong that it could digest the stomach if not for a mucus lining protecting the organ.
For example, if you give someone sodium bicarbonate (baking soda) to drink, as the pH of the stomach increases, you expect the stomach to excrete more hydrochloric acid to bring the pH down. If the stomach is unable to produce hydrochloric acid, a diagnosis of hypochlorhydria (low stomach acid production) is made.