 Hydrochloric acid, a material that can be very corrosive in which we should only handle with protective gloves and safety goggles. And yet, you can find this substance right inside your body. Stomach acid is in fact hydrochloric acid with a pH of around 1 to 2. So let's explore the role of stomach acid in our bodies. Stomach acid has two key roles. Because it is very acidic, with a low pH, it serves to denature any consumed protein by breaking down its globular structure into amino acid chains. If you wish to learn more about proteins and their structures, there is a lesson right here on our channel. Stomach acid also activates a few important digestive enzymes such as proteases and lipases. These enzymes can only function at a low pH. Proteases break apart the long amino acid chains into smaller chains or even further into amino acids. What do you think lipases do? Pause the lesson to think about this and resume once you are ready. Lipases break apart lipids or fat molecules. But how do our stomach walls contain this acid? When a substance with such a low pH corrode through the walls, the answer lies in the type of cell found on the internal stomach lining. These cells secrete mucus, which protect stomach acid from breaking down your stomach. But when there is too much of stomach acid or when it is pushed upwards towards the esophagus past the cardiac sphincter, this medical condition is known as acid reflux. This can happen due to an excessive amount of food being consumed in a short period of time or due to certain types of food such as acidic or spicy food or food with a high fat content. Considering that this is caused from an excess of stomach acid, how do you think it can be neutralized? Pause the lesson, think about it and resume when you are ready. Consuming something alkaline can help relieve the burning sensation. This is an example of a real-life acid-base neutralization reaction. Antacids are a possible treatment and can be purchased at almost any pharmacy or supermarket. All depending on the brand of the antacid, it could contain the following substances calcium carbonate, magnesium carbonate, sodium hydrogen carbonate. Let's use calcium carbonate as an example. This reaction yields a salt, calcium chloride, water, and carbon dioxide gas. This can help relieve the burning sensation caused by acid reflux.