2.6. Translate the sentences into English:

1. Ядро контролирует деятельность каждой клетки. 2. Кожа, волосы, шерсть, перья и рога являются внешними тканями. 3. Не только протоплазма, но и стенки клеток состоят из протеина. 4. Протеин придает скелету эластичность. 5. Роль протеинов очень велика, так как они необходимы для роста организма.

3. The carbohydrates

3.1. Read and translate the text using a dictionary:

The carbohydrates comprise about three-fourths of all dry matter in plants. They form the woody framework and also are the chief reserve food in such plants parts as seeds, roots and tubers.

Carbohydrates usually serve as the chief fuel to maintain the body temperature and to furnish the energy for all body processes.

The term carbohydrates means that these compounds contain three elements: carbon, hydrogen, and oxygen. The carbohydrates consist of two groups: the sugars, which are simple in composition, and the groups of much more complex compounds - polysaccharides. Some of the carbohydrates have a high value as feeds and the animals digest them easily. On the other hand complex carbohydrates which form the woody fiber of plants have a low value for stock because the animals digest them with difficulty.

3.2. Answer the following questions:

1. What plant parts do you know?

2. What are the chief functions of the carbohydrates?

3. What does the term carbohydrate mean?

4. Are the sugars complex in composition?

5. Do the animals digest complex carbohydrates easily?

6. What is the energy necessary for?

3. Find the meaning of the following words and word combinations used in the text: углеводы, корнеплоды, клубни, служить, водород, обеспечивать энергией, скот, высокая ценность, простые по составу, переваривать (усваивать), поддерживать температуру тела, аминокислоты.

4. Form the comparative and superlative degrees of the following words: high, simple, large, complex, difficult, poor, low.

3.5. Give antonyms to the following words: сomplex, high, external, undigested, usually, low, simple.

3.6. Translate the sentences into Russian:

1. Straw is less digestible than hay. 2. Normal life ceases in the absence of carbohydrates. 3. In foods the carbohydrates occur as sugars, starches, cellulose or fibre and the organic acids. 4. Cattle, sheep and goats have more complicated digestive tracts than other animals. 5. Shortage of water is a limiting factor in digestion. 6. The largest part of the fat stored in the bodies of farm animals is formed from the carbohydrates of the food.

3.7. Read and translate the text with a help of a dictionary. Then divide it into the main paragraphs and name each of them:

Carbohydrates are one of the main types of nutrients. Plants make carbohydrates during photosynthesis and store them as any of the saccharides (sugars). They are used primarily for energy in the body. A certain amount can be stored in the liver and muscles as glycogen, and the rest is stored as fat.

All carbohydrates are made up of carbon, hydrogen and oxygen. Carbohydrates are divided into simple and complex, depending on their chemical structure. Simple carbohydrates include sugars found naturally in foods such as fruits, vegetables, milk, and milk products. They also include sugars added during food processing and refining. Complex carbohydrates include whole grain breads and cereals, starchy vegetables and legumes. Many of the complex carbohydrates are good sources of fiber.

Carbohydrates serve several biochemical functions including as the fuel for cellular metabolism, in several biosynthesis reactions, to form structural elements, such as chitin in animals and cellulose in plants, for an organism's fertilization, development, blood clotting and immune system function.