Text 9a Animal and Vegetable Proteins

The proportions of amino acids іn аny vegetable food (cereals, nuts and seeds, potatoes) differ from those needed by man. For example, wheat is low in lysine, maize is low in tryptophan, peas and beans are low in methionine. These proteins are said to have low biological values, because the quality of a protein depends on its ability to supply all the essential amino acids in necessary amounts. Mixtures of such foods complement each other and its nutritional value rises.

Most animal proteins (from meat, fish, milk, cheese and eggs) have a high biological value. The reason for this is that man is a part of the animal world. The proteins of animals are like those of man-and can be utilized by us with the minimum of waste.

Nevertheless the nutritional advantages of aminal foods over vegetable foods in practice He more in the presence of such nutrients as vitamin В і₂₎ iron and vitamin D than in the protein. Because there is no way in which excesses of amino acids can be stored in the body, they will be most efficiently used if a complete assortment is supplied to the body about the same time. This can be achieved by eating a mixed diet at each meal (the total energy content of the diet must be adequate).

So mixtures of vegetable protein foods (beans on toast) or, of animal and vegetable protein foods (fish and chips, bread and cheese) have a sound physiological basis.

Unit 10

Вивчіть подані слова i словосполучення

antibody n. антитіло

coeliac disease хвороба черевної порожнини

Text 10 A. Health Aspects of Proteins.

About one-third of the protein in the diet comes from .plant sources and two-thirds from animal sources. The amount of protein in nuts and dried peas and beans is very high — about the same as in meat, fish and cheese. Cereals are also rich in protein: wheat, maize, and rice are the main sources of protein for many people in the world. The amount of protein in most root vegetables is small, but potatoes give necessary amounts.

The amount and type of protein in the diet will not balance the needs for growth, repair and maintenance of the body. There always will be excesses of some amino acids and usually an excess of total protein. These will be changed into glucose in the liver or be directly oxidized to provide heat and energy. That is why it is important to know that diets contain necessary energy in the form of carbohydrate-and fat before expensive proteins are added. These proteins can be utilized only when no other nutrient can be substituted.

As for newborn infants, they can absorb some proteins from their mother's milk» including antibodies which provide protection from infection. Some individuals can react to certain other food proteins. For example, those with coeliac disease react to gluten, others react to cow's milk protein. Some beans including soyabeans contain proteins which are harmful unless well cooked.

Unit 11

Запам'ятайте вимову поданих нижче хімічних термінів. Відшукайте нижче їх переклад:

calcium, magnesium, sodium, chlorine, potassium, haemoglobin, iron, sulphur, cobalt, copper, chromium, fluorine, iodine, manganese, zinc

натрій, кальцій, гемоглобін, йод, магній, кобальт, хлор, фтор, мідь, калій, цинк, хром, марганець, сірка, залізо

Вивчіть подані слова i словосполучення

mineral n мінерал; а мінеральний, неорганічний

composition n склад

fluid n рідина, рідинне середовище; а рідкий

adjunct п додаток, доповнення

release n виділення; у вивільняти

consider v розглядати; вважати

equal а рівний, однаковий;

equally advоднаковою мірою; однаково

trace n слід; хім. незначна кількість (речовини);

trace elements мікроелементи

Text 11A. Minerals and Their Functions

Minerals are inorganic elements. Most of them can be found in the body, but only fifteen of them are known to be essential and must be taken from food.

The main three functions of minerals are:

1. They are constituents of the bones and teeth. These include calcium, phosphorus and magnesium.

2. As soluble salts they help to control the composition of body fluids and cells. These include sodium and chlorine in the fluids outside the cells; and potassium, magnesium and phosphorus inside the cells.

3. They are essential adjuncts to many enzymes, and other proteins such as haemoglobin. Iron and phosphorus are necessary for the release and utilization of energy.

These seven elements (calcium, phosphorus magnesium, sodium, chlorine, potassium and iron) are needed in the greatest quantities in the diet or are present in the largest amounts in the body tissues. These, together with sulphur, may be considered as the major minerals.

The rest of the minerals, including cobalt, copper, chromium, fluorine, iodine, manganeze and zinc, are equally essential but needed in much smaller quantities. They are called trace elements. It's necessary to remember that a large excess of most of these elements can be poisonous.

Unit 12

Вивчіть подані слова i словосполучення

dietary deficiency- недостатність дієтичного харчування

malnourished infants - діти, що недоїдають

thyroid gland- щитовидна залоза

Text 12 A. Trace Elements

Cobalt, copper, chromium, fluorine, iodine, manganese, selenium and zinc are called trace elements. They are necessary to a man, but not in large quantities. We do not know the exact roles of these minerals, because some of them have recently been found to be essential, but dietary deficiencies of some are still unknown. The utilization of, one may be affected by the amounts of other elements present.

Cobalt can be used by man only in the form of vitamin B₁₂.

Copper is associated with a number of enzymes. Its deficiency has been observed in malnourished infants. The main sources of copper in the average diet are meat, bread and other cereal products, and vegetables.

Chromium is involved in the utilization of glucose and widely distributed in foods.

Fluorine increases the resistance of bones and teeth to decay. Drinking water is an important source, but the natural content is often very low The only other important sources of fluorine in the diet are tea, sea-food (especially fish whose bones are eaten) and, if eaten, fluoridated toothpaste.

Iodine is an essential constituent of hormones produced by the thyroid gland. The most important source of iodine is sea-food. Its amount in vegetable and cereal foods depends on the level in the soil. Because of the use of iodines in animal feed, milk and milk products, meat and eggs are important sources of iodine in the diet.

Manganese is associated with a number of enzymes. Tea is very rich in manganese, and plant products are in general much better sources of manganese than the animal products

Selenium is needed for an enzyme in the red blood cells-The main dietary sources of it are meat, fish and cereal products.

Zinc is presenter a wide range of foods, particularly in association with protein, and meat and dairy products are its excellent sources.

Unit 13

Вивчіть подані слова i словосполучення

replace v заміняти

tannin п хім. танін

distribute v розподіляти; поширювати

widely distributed (wide-spread) дуже поширений

liberation п звільнення; виділення

requirement n потреба

Text 13 A. Major Minerals

Calcium, phosphorus, magnesium, sodium, chlorine, potassium, and iron are known as major minerals.

Iron. Healthy people contain about 3 to 4 g of iron, more than half of which is in the form of haemoglobin, the red pigment of blood. Also it is present in some organs such as the liver. If food has not enough iron to replace body's losses, anaemia may result. The-absorption of iron from food is low. Most readily it is absorbed from meat (up to 25 per cent). Less than 5 per cent of the other forms of iron such as those in eggs and vegetables or added to flour is absorbed. The exact amounts depend on other factors in the diet, for example, it is increased by vitamin C, but decreased by the tannins in tea. Some other important sources of iron are eggs, cereal products, potatoes and vegetables.

Calcium. Calcium is the most widely distributed mineral in the body. All but about I per cent of it is in the bones and teeth. It gives them strength. About 10 g of calcium are essential for the contraction of muscles including the heart muscle, for nerve function, for the activity of several enzymes. Too little calcium in the body causes different diseases of bones and teeth. Only about 20—30 per cent of the calcium in the average diet is normally absorbed. Few foods besides milk and cheese, and most bread contain significant amounts of calcium. It is very important that these foods are included in the diet, especially for children whose needs are greatest.

Phosphorus. Phosphorus is the second widespread mineral in the body in the form of various phosphates, which perform a lot of essential functions. Calcium phosphates provide the strength of the. bones and teeth Inorganic phosphates are major constituents of all cells. Phosphates play an important role in the liberation and utilization of energy from food. They are also constituents of nucleic acids and some fats, proteins and carbohydrates. Because phosphorus is present in nearly all foods, its dietary deficiency is unknown in man. The main sources of phosphorus in the diet are milk and milk products, bread and other cereal products, meat and meat products.

Text 13 B. Major Minerals

Magnesium. Most of the magnesium in the body is present in the bones, but it is also an essential constituent of all cells. It is necessary for the functioning of some of the enzymes which are involved in energy utilization. Magnesium is wide-spread in foods, especially4hose of vegetable origin because it is an essential constituent of chlorophyll.

Sodium and chlorine. All body fluids contain salt (sodium chloride). These elements are involved in maintaining the water balance of the body. Sodium is also essential for muscle and nerve activity. Salt requirements are closely related to water requirements. Salt intake may, however, be restricted in certain kidney diseases, besides salt should not be added to infants diets.

It is essential for life that the concentration of sodium and chloride in the blood is maintained within close limits, because an excess of (added) salt in the diet is readily absorbed. Control of sodium in the blood is achieved by its excretion through the kidneys. Also it is lost through sweat. Sodium and chlorine are comparatively low in all not-processed foods, but salt is added to very many prepared foods. For example, salt is low in fresh meat but high In bacon, sausages, and most other products. Salt is added to butter, margarine, cheese, bread and some other foods hiring home cooking and on the plate.

Potassium. Potassium is present in the fluids within the body cells where its concentration is carefully controlled. Most of the potassium in the diet is absorbed and the excess is excreted through the kidneys. The main sources of potassium are vegetables, meat, and milk.

Unit 14

Вивчіть подані слова i словосполучення

vitamin n вітамін

believe v вірити

pure о чистий, без домішок;

pure milk незбиране молоко

change v міняти, змінювати

soluble а розчинний;

fat-soluble жиророзчинний;

water-soluble водорозчинний

absence n відсутність;

absent а відсутній

presence n присутність, наявність;

present] а присутній, наявний

Text 14 A. Vitamins

Until the beginning of the 20-th century it was believed that pure proteins, fats, carbohydrates and some other inorganic elements were the only components of a diet necessary for health, growth and reproduction. But later this view had to be changed when it was found that some additional materials were also essential for the body. These materials appeared to be of two types: fat-soluble ("A") and water-soluble ("В''). Also it was discovered that they contained, active components or vitamins.

Fat-soluble vitamins are associated with fatty foods. This complex is now known to include vitamins A, D, E and K. The rest relate to water-soluble vitamins. The vitamin В complex includes thiamin (vitamin B₁), riboflavin (vitamin B₂), niacin (or nicotinic acid), folic acid, vitamin В6, vitamin B₁₂, biotin and pantothenic acid. Vitamin С is also water-soluble, but occurs in different foods from the B-vitamins. Many of these vitamins exist in more than one chemical form.

Вивчіть подані слова i словосполучення

malaise n нездоров'я, нездужання

lesion п пошкодження, ураження

blindness n сліпота

pellagra n пелагра

blood n кров;

bleeding n кровотеча

wound n рана

heal v заживати, загоюватися

scurvy n цинга, скорбут

faddist n дивак

Text 14 B

Read and translate the following text. Entitle it:

In order to estimate health aspects of the proteins, fats, carbohydrates, minerals in food, about a half century ago scientists separated these substances in pure forms from somе natural foods. When animals were fed with those mix-|attires of purified nutrients, many of them sickened and died. It shows that the absence of any vitamin from the diet, or, more commonly in practice, its presence in insufficient amounts, leads to both general and specific symptoms. The most common general symptoms are, as with deficiencies of many other things, a feeling of malaise and restriction of the growth of children.

It is known that vitamin A is essential for vision. Deficiency of this vitamin leads to eye lesions and even to complete blindness. A lack of some vitamins of the vitamin В complex may result in skin diseases (for example, in pellagra, in which skin becomes dark and scaly, especially when it is exposed to light), characteristic anaemias, degeneration of nerve cells.

Vitamin С is necessary for the maintenance of healthy connective tissue. Its deficiency results in bleeding, especially from small blood vessels, and wounds heal more slowly. Scurvy follows, and, if the deficiency is prolonged, death results. Mild deficiencies may occur in infants who are given cows milk, in people eating poor diets (particularly the elderly), and in food faddists eating little but whole cereals which contain no vitamin C.

Excessive intakes of water-soluble vitamins are not dangerous, and have little effect. But excessive intakes of fat-soluble vitamins, accumulating in the liver, can be poisonous.

Unit 15

Вивчіть подані нижче слова і словосполучення:

convert v перетворювати; переробляти

dripping п топлений жир

spinach n шпинат

cabbage n капуста (качанна);

cabbage-head капустина

cauliflower n цвітна капуста

poison n отрута;

poisonous а отруйний

retinol n ретинол

carotenes n каротин

anaemia n анемія, недокрів'я

toxic а токсичний, отруйний

clotting n скипання (крові)