Archive for December, 2009

Choice of Food

Wednesday, December 2nd, 2009

Normally, with a well-balanced diet, the organism receives adequate amounts of all the necessary elements through the food and water consumed. When, however, any one element is lacking, various diseases, sometimes very serious, may occur.

When soil lacks iodine, it is necessary to add it to the common salt. The water of the river Neva is considered to be the purest and the best drinking water in the world, but this purity is its main shortcoming. One of Leningrad water-works has begun to add fluorine to the drinking water since absence of fluorine frequently causes teeth trouble. What is more, Swedish scientists dis­covered that people who systematically use soft water are much more liable to develop cardiovascular diseases.

Some difficulties in supplying chemical elements to the organism arise because most substances composing the tissues and organs cannot be synthesized directly from elements. For instance, proteins are built up of different combinations of twenty-two amino acids, of which only ten can be synthesized by the organism, while the remaining twelve must be obtained ready-made. Besides, even when we ourselves produce the amino acids, the nitrogen necessary for the purpose must be supplied in the form of organic compounds. The same is true of glucose which cannot be synthesized directly from carbon and hydrogen in the organisms of animals, and this is why ready-made hydro­carbons are used to produce it.

Of the many substances which are absolutely essential to the organism, even in small amounts, mention must be made of vitamins. They are indispensable to life.

The choice of food is very important. Bees are an excellent example. A queen-bee which feeds on so-called royal jelly from its first days till the end of its life lives for two or three years. The worker bees receive this miraculous food for only the first two days of their lives and are given coarser food from the third day on. As a result they do not become completely fertile females and live onfy for two or three weeks.

Tags: , , , , ,

Purpose of Food #2

Tuesday, December 1st, 2009

Another purpose of food is to provide the organism with energy resources. The building of new molecules is in itself a process which calls for a certain amount of energy. Then there are the muscles and all the other organs of our body, most of which never stop functioning, not even for a single minute. Even when one is asleep the heart goes on working, as do the respiratory muscles, the liver, kidneys, alimentary tract, and endocrine glands. Even the brain goes on expending energy on quite a large scale, although this is the one we notice least.

Energy losses can be quite easily restored. Used as ‘fuel’ are fats, carbohydrates and, to a certain extent, proteins which ‘burn’ in the- organism to form carbon dioxide and water. The organism actually consumes only one kind of fuel — glucose. Fats and proteins are first converted to glucose, before they become an energy-supplying material.

It is easier to provide the organism with fuel than to supply it with all the necessary building materials. Human body consists mainly of carbon, nitrogen, oxygen and hydrogen, with small, sometimes negligible, amounts of other chemical elements.

Gabriel Bertrand, a French biochemist, calculated that the body of a man weighing about 100 kilograms contains:

oxygen 63 kg sodium 260 g
carbon 19 kg potassium 220 g
hydrogen 9 kg chlorine 180 g
nitrogen 5 kg magnesium 40 g
calcium 1 kg iron 3 g
phosphorus 700 g iodine 0.03 g
sulphur 640 g

Fluorine, bromine, manganese and copper are present in even lesser amounts. It is quite possible that all the other elements, even those which are not very active chemically, such as gold, can be found in the organism, but we still do not understand the part they play.

Tags: , , , , , ,