Text № 5 «from the history of VItamins»

1. Прочитайте текст и скажите, какое открытие было сделано польским ученым.

Выделите самое главное, говоря о функциях витаминов A, B, C.

 

In 1911 the young Polish scientist, Casimir Funk, published a book in which he described experiments by means of which he extracted a substance from rice hull¹ which when fed to fowl in very minute quantities cured them of the paralysis of poly-neuritis within a few hours. For this white crystalline substance he gave a name, Vitamine (“Vita” for life, “amine” the name of a certain class of chemical compounds). Though it was soon shown that the life giving material contained no amine the name remained, not only with the researchers but also with the public, and it stayed though it has dropped its “e”. Naturally the first vitamin work was biological. Many organic chemists have attempted to find the exact chemical structures of these extremely complex materials. The principal members of the vitamin groups are A, B, C, D.

For the most part we obtain our vitamins directly from foods but there are amendments to the rules.

Vitamin A can be obtained from fish livers and a variety of other foods of animal origin, or our bodies can manufacture it from carotene found in green leaves and some tubers.

The body can manufacture its own vitamin D from the ergosterol on or near skin, if exposed to sunshine. The functions of the vitamins are very varied, interesting and important.

Vitamin A. It is essential for eyes, nerves growth, reproduction and lactation and the maintenance of bodily vigor at every stage of existence. Life without vitamin A is hardly worth while. Green vegetables, milk, bitter and cod liver oil contain vitamin A.

Vitamin B. The exact amount of vitamin B for optimum human health is not known; but the minimum intake necessary to prevent beriberi or other severe nervous disturbance has been well established.

In common with most of other vitamins vitamin D is necessary for normal growth. There is probably some connection between its growth and appetite-inducing properties.

Vitamin C. The citrus fruits (oranges, lemons, grape-fruits) are sources of vitamin C. Tomatoes, raw cabbage and onions also contain vitamin C. Apples, bananas, carrots and potatoes contain some, but they are important sources only if eaten in large amounts.

If the shortage of vitamin C causes scurvy, the teeth fall out, if the shortage is less, they rot out.

1 – шелуха риса

 

Text № 6 «B – COMPLEX VITAMINS»

Прочитайте текст и дайте характеристику витаминов группы В.

 

Thiamine which is designated as B₁, is one of the B vitamins that are often called the B -complex vitamins. Thiamine is destroyed by prolonged heating. The shorter the cooking time and the less the amount of water used, the less is the loss of thiamine. Important sources of thiamine are: whole grain bread and cereals, meat, milk, liver, nuts, vegetables.

Riboflavin is another of the D vitamins and was called vitamin B₂. It is essential to growth and due to it a high level of positive health is maintained. Riboflavin is little affected by heat but easily destroyed by baking soda. It is also readily destroyed by light and is soluble in water. Foods that are good sources of riboflavin are: whole grain or enriched bread and cereals, cheese, eggs, green leafy vegetables¹, meat, liver, milk.

Still another of the B vitamins is niacin. Until it was recognized as vitamin, this substance was known to chemists as nicotinic acid. Niacin is essential for growth and normal functioning of the skin and the digestive tract. Niacin is stable to air, heat and light, however, it is readily soluble in water and especially hot water. Foods that furnish niacin are: enriched or whole grain bread and cereals, meat, liver.

In many states thiamine, riboflavin, niacin, and iron are more and more commonly being added, flour, rice and other processed cereals to enrich them with these needed food constituents.

Pyridoxine, often referred to as vitamin B₆, is essential for good health. It is especially involved in certain cellular activities and in the utilization of other foods by the body. This vitamin is soluble in water and stable to heat, alkalies and acids, however, it oxidizes readily and is destroyed by light. Good food sources are heart, liver, meat, seeds and whole wheat.

Certain relationships among the vitamins make for better use of these nutrients in the body. For example, thiamine, riboflavin, and niacin are all essential in the utilization of carbohydrates. Vitamin B₆ is essential in the utilization of protein. Vitamin D is closely related to the metabolism of calcium and phosphorus and in its absence these minerals are not efficiently used in bone formation.

Many other vitamins than those presented here have been discovered, but their role in nutrition has not been determinated yet.

1 – green leafy vegetables – овощи со съедобными листьями (напр. салат)

 

 

Text № 7 «ESSENTIAL MINERALS»

Прочитайте текст и перечислите функции представленных минеральных веществ.

Выразите свою оценку значения минеральных веществ для жизнедеятельности организма.

 

Our body needs certain elements known as minerals, or ash¹ constituents. They are calcium, chlorine, copper, iodine, iron, magnesium, sodium, sulphur, zine, and possibly aluminium, cobalt, fluorine, nickel, molybdenum and silicon. Due to the very small amount required of each, the six last named minerals along with copper and zine are usually referred to as trace elements².

Calcium is required for all tissues but especially for bones and teeth. It is essential in the coagulation of blood, the beating of the heart, the irritability of nerves, cell activity, and the maintenance of the neutrality of the body. Foods that are important sources of calcium are: bread, carrots, cheese, egg yolk, ice-cream, milk, oranges, turnips, green and leafy vegetables.

Phosphorus, too, is necessary in all tissues and essential in the oxidation of carbohydrates. It helps in the regulation of the neutrality of the blood, in the conductivity of nerve impulses and in the controlling of cell activity. Important sources of this food constituent are: cheese egg yolk, fish, ice-cream, leafy vegetables, meat, liver, legumes, milk, whole grains.

Iron is necessary to form hemoglobin, a substance in the blood, which carries oxygen to the cells and plays an essential role in the body functions and the activity of cells. Valuable food sources of iron are: wheat, bread, and cereals, whole grain, egg yolk, fish, liver, potatoes. Copper is widely distributed in foods and most of those that are good sources of iron are also good sources of copper. Iodine aids in the regulation of general health and of the nervous system. When iodine is lacking in the diet, the thyroid gland is unable to produce thyroxin, a hormone which is necessary for all the oxidative reactions of the body. Sources of iodine are cod liver oil, salt water fish, sea foods, vegetables, cereals, dairy products, and fruit produced on soils of good iodine content and water supply.

1. зола

2. микроэлементы

 

Text № 8 «WHEAT»

1. Прочитайте текст и составьте план на русском языке.

2. Пользуясь планом, изложите основное содержание текста.

3. Расскажите на английском языке:

а) о структуре зерновки пшеницы;

б) о внешних особенностях и характеристиках разновидностей пшеницы

 

Neither the geographical, the historical, nor the biological origin of wheat is known. The evidence as exists seems to point to Mesopotamia as the original home of wheat, although there is a belief that the plant once grew wild in the Euphrates and the Tigris valleys and spread from these regions to the rest of the world.

The most ancient languages mentions of man notably in the earliest Swiss lake dwellings is proof of its antiquity. We also have evidence that wheat was cultivated in China 3,000 years B.C., and that it was the chief crop in ancient Egypt and Palestine.

Wheat is the most important of the cereals. It can grow in almost any kind of soil and in any climate. Thus, it is one of the most widely grown crops in the world.

The grain of wheat is a seed. It may by regarded as consisting of three parts: the germ or embryo which produces the new plant; the starchy endosperm, which provides the food for the new plant when the embryo first starts to grow; the various outer coverings constituting the bran of the grain. The protein of wheat which is contained in the endosperm is called gluten from its glue-like tendency to hold starch particles together.

Different varieties of wheat grown under diverge conditions of soil, climate and pedigree¹ vary greatly in appearance and characteristics. In appearance, wheat may be red or white according to the colour of the bran or outer skin of the grain; in characteristics it may be hard or soft, “strong” or “weak”. Strong wheats give the best bread-making flour, weak wheats – the biscuit and self-rising flour.

Wheat may be divided into two classes, winter wheat and spring wheat. Spring wheats grown in suitable climate are usually strong, whereas winter wheats are usually weak.

1 – родословная

 

Text № 9 «RYE»