2014- acids4

SECTION EUROPÉENNE Épreuve spécifique de sciences physiques en anglais ACIDS AND BASES in the body

Watch the video untitled “acids 2” and study the following documents: The stomach’s cells produce hydrochloric acid, a component of the gastric juice that helps humans digest food. It helps break food into smaller pieces that are easy to digest. Hydrochloric acid also helps the stomach maintain its acidic environment. An excess of production of hydrochloric acid leads to sour stomach or ulcer stomach. During exercise, the muscle cells produce lactic acid as a source of fuel for the mitochondria, which produce energy. The muscles are able to work longer and harder. Lactic acid is very important for human body but excesses leading to heart disease, Diabetes, Fibromyalgia, muscular cramps etc. So it must be managed correctly in intake of food sources and the elimination of the end product. The carbonic acid is the name given to solutions of carbon dioxide in water. The hydration reaction of CO2 is the reaction of dissociation of a hydrogen ion (H+) from the resulting carbonic acid, leaving hydrogen carbonate (HCO3−) dissolved in the blood plasma. Carbonic acid is an intermediate step in the transport of CO2 out of the body via respiratory gas exchange. This reaction is reversed in the lungs, where it converts the hydrogen carbonate back into CO2 and allows it to be expelled. If the level of CO2 is not well controlled, your blood is in acidosis, it means that the pH of your blood is too acidic.

TASK: your are a science teacher and you want to explain to your students thanks to your knowledge and the content of the video, what the properties, the uses and dangers of acids in our body are. You can use the guidelines below to organize or support your presentation; feel free to use them in any order you like.    

Define the pH scale and give examples for each part of the scale. Write the equation of hydration of carbon dioxide and explain why it’s an acid. Explain the difference between an acid and a base Explain why acids are important for our body’s functions but how they can become dangerous.

2014- acids4