Vitamins

A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. If a molecule can be synthesized in the body, it is not a vitamin. The single exception to this rule is vitamin D which can be synthesized in the skin, but only when exposed to sunlight and Niacin (B3) which itself can be synthesized in the liver in small amounts. The term vitamin does not also include other essential nutrients such as minerals, fatty acids, or amino acids (which are needed in larger amounts than vitamins).

Vitamins are classified as either water-soluble or fat-soluble. There are 13 universally recognized vitamins: 4 fat-soluble (A, D, E, and K) and 9 water-soluble (8 B vitamins and vitamin C). Fat-soluble vitamins are stored in the body's fatty tissue, so they do not need to be ingested every day. Water soluble vitamins cannot be stored, with the exceptions of В₁₂ and Folic Acid and must be ingested frequently for optimal health. They are easily excreted through the urine.

Vitamins have diverse biochemical functions. For example, vitamin A helps to develop and maintain body tissues such as bone and skin; it also helps the body’s vision, nervous system functioning, reproduction, and growth. The B vitamins are responsible for increasing the production of fats, proteins, and carbohydrates as well as assisting with metabolism, building red blood cells, and maintaining the protection of the nervous system. Vitamin C helps form tissues, cells, bones and teeth; heals wounds; and improves the immune system’s performance. Vitamin E protects the outer cell membranes from harm, thus assisting the immune system in fighting off diseases.

A diet naturally high in vitamins and minerals can be the best defense against many diseases. You can develop health problems (deficiency disease) if you do not get enough of a particular vitamin. But it is also important to remember that high doses of certain vitamins can cause vitamin poisoning.

Exercise 6. Answer the questions:

1. What vitamins can be synthesized in the body?

2. How are vitamins classified?

3. How many vitamins are universally recognized?

4. Why is it unnecessary to ingest fat-soluble vitamins daily?

5. How are water-soluble vitamins excreted out of the body?

6. What functions do vitamins have?

7. What are B vitamins responsible for?

8. What can high doses of certain vitamins cause?

Exercise 7. Find words or word combinations in the text denoting the following:

1. a condition, produced by a lack of vitamins or other essential substances;

2. a condition of high storage levels of vitamins, which can lead to toxic symptoms;

3. an organic compound required as a nutrient in tiny amounts by an organism, which cannot be synthesized in sufficient quantities within the body;

4. a chemical compound, whose molecules contain carbon;

5. a group of vitamins stored in the body's fatty tissue;

6. a group of vitamins which cannot be stored in the body.

Exercise 8. Find corresponding equivalents in the text:

Різноманітні біохімічні функції, викликати отруєння вітамінами, захищати зовнішню клітинну оболонку від пошкодження, органічна сполука, покращувати продуктивність імунної системи, розвивати авітаміноз, виділяти з сечею, допомагати підтримувати тканини тіла, у достатній кількості, єдиний виняток з цього правила, жирні кислоти та амінокислоти, потрібно споживати щоденно, необхідні поживні речовини, накопичуватися у жировій тканині, водорозчинні вітаміни, жиророзчинні вітаміни.

Exercise 9. Match the words with their definitions:

Exercise 10. Put the words in the correct order to make questions:

1. can / be / How / vitamins / classified?

2. Where / produced / vitamins / are / synthetic?

3. helps / change / into energy / What / the body cells / carbohydrates?

4. folate / does / form / help / What?

5. for / What / essential /is / biotin?

6. the body / leave / vitamins / do / How / water-soluble?

7. What / the body’s fatty tissue / vitamins / stored / are / in?

8. the first / isolated / Who / vitamin complex?

Exercise 11. Put questions to the underlined words:

1. Vitamin D can be synthesized in the body.

2. Water-soluble vitamins must be ingested frequently.

3. Vitamins have diverse biochemical functions.

4. High doses of certain vitamins can cause vitamin poisoning.

5. Vitamin C helps form tissues, cells, bones and teeth.

6. Vitamin E protects the outer cell membranes from harm.

7. Deficiencies of vitamins are classified as either primary or secondary.

8. Many types of water-soluble vitamins are synthesized by bacteria.

Exercise 12. Ask questions beginning with the question word given in brackets:

1. Cashmir Funk was the first scientist who used the term “vitamine”. (Who?)

2. In the 1930s a scientific discovery demonstrated the biochemical functions of the vitamins. (When?)

3. Vitamins have been commercially produced since 1930. (Since what time?)

4. Niacin can lower blood cholesterol levels. (What?)

5. Vitamins were given letters to go with their chemical names to simplify discussion about them. (Why?)

6. Fat-soluble vitamins are absorbed through the intestinal tract. (How?)

7. Water-soluble vitamins dissolve easily in water. (Where?)

8. Vitamin C promotes wound healing. (What?)

Exercise 13. Translate the questions into English:

1. Який орган накопичує вітамін B12?

2. Хто був нагороджений Нобелівською премією за відкриття деяких вітамінів?

3. Що слід включати до раціону?

4. Скільки є водорозчинних вітамінів?

5. Які вітаміни не слід вживати щоденно?

6. Чому жиророзчинні вітаміни не вживають щоденно?

7. З яких джерел можна отримати вітаміни групи В?

8. За яких умов тіло може виробляти вітамін D?

Exercise 14. Put the sentences into the correct order to explain the term “vitamin”:

__Water soluble vitamins cannot be stored, with the exceptions of В₁₂ and Folic Acid and must be ingested frequently for optimal health.

__Vitamins are classified as either water-soluble or fat-soluble.

__There are 13 universally recognized vitamins: 4 fat-soluble (A, D, E, and K) and 9 water-soluble (8 B vitamins and vitamin C).

__A vitamin is an organic compound that is needed in a small amount for normal growth and activity of the body.

__Fat-soluble vitamins are stored in the body's fatty tissue, so they do not need to be ingested every day.

Завдання для самостійної роботи студентів (СРС)

Exercise 1. Topic Vocabulary:

Exercise 2. Read the word combinations and sentences with the new words and translate them into Ukrainian:

Source: source data; source of anxiety; source of bleeding; source of infection; source of radiation.

Date: 2015-12-12; view: 1237; Нарушение авторских прав