B. Vital Functions of Minerals
Minerals have many vital functions in the body. The skeletons of vertebrate animals are composed chiefly of minerals (nearly all calcium and phosphorus), and minerals are essential constituents of the soft tissues and fluids of the body. Phosphorus is a vital ingredient in the proteins that characterize the nuclei of all body cells, and also is a component of certain other important proteins such as the casein of milk. The phospholipids, which are phosphorus-containing milk fat-like substances, are essential parts of all living protoplasm. The power of the blood to carry oxygen is due to hemoglobin, the iron-protein compound in the red blood corpuscles. The acidity and alkalinity of the digestive juices is due to mineral compounds. Thus, the acidity of the gastric juice in the stomach, which is necessary for the action of the enzyme, pepsin, is due to hydrochloric acid, derived from sodium chloride and other chlorides that are present in the blood. The osmotic pressure which is necessary for the transfer of nutrients and waste products through the cell walls is largely dependent on the concentration of mineral salts in the lymph and in the cells. A serious lack of calcium in the blood such as may occur in milk fever of cows and in certain advanced cases of rickets is the cause of convulsions and tetany. Vocabulary List break (broke, broken) (v) - ломать to be due to smth. - быть обусловленным, являться следствием чего-либо nutrient (n) - питательное вещество acid, acidity – кислота, кислотность alkali - щелочь rickets (n)- рахит milk fever - молочная лихорадка a lack (of smth.) (n) – недостаток чего- либо gastric juice - желудочный сок transfer (v) - передавать, переносить in order to.. - для того, чтобы… advanced case – запущенный случай (болезни) Exercise 4. Read and translate the text "Vital Functions of Minerals". Exercise 5. Render the text "Vital Functions of Minerals" in English, answering the following questions: 1. Каковы важнейшие функции минеральных веществ в организме? 2. Где в организме животного находится фосфор? 3. Чем обусловлена способность крови переносить кислород? 4. Что представляет собой гемоглобин? 5. Какое минеральное вещество обуславливает кислотность желудочного сока? 6. Для чего необходимо осмотическое давление? 7. От чего оно зависит? 8. Что может явиться причиной конвульсий и тетании?
Lesson 4 Iron and Copper An adequate supply of iron is essential for animals because the oxygen needed by the tissues for the life processes is transported in the blood by the haemoglobin, which is an iron-containing compound. Iron is also usually present in the nuclei, or life centers, of the body cells which control their activities. Iron compounds play an important part in the oxidation of nutrients in the cells. In spite of the importance of iron the animal body contains a very small amount. Iron forms only about one part in twenty-five thousand by weight of our bodies. The tissues of a fullgrown, healthy person contain only 1/10 ounce of this mineral. Recent investigations have shown that for haemoglobin formation in the body small traces of copper must be provided in the food, as well as an ample supply of iron. Traces of copper are therefore essential for animal life, although this mineral is a violent poison when any considerable amount is taken into the body. It has been found that copper is not a part of the haemoglobin, but that it is necessary to enable the body to produce this compound. If animals are fed a diet low in iron and copper nutritional anemia will result. Exercise 1. Read the text "Iron and Copper" and answer the following questions in Russian: 1. How is oxygen transported in the blood? 2. Does haemoglobin contain iron? 3. What part do iron compounds play in the body? 4. Does the body contain much iron? 5. What is copper needed for by the body? 6. What is the role of copper? 7. What will result from a diet low in iron and copper?
Lesson 5
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