Classification of nutrients
The foods you eat in daily diet provide the nutrients we used to form new tissues during growth, to replace tissue destroyed, and as a source of energy to meet the body's caloric needs. At the same time, contain substances necessary for the use of food. The functions of nutrients can be divided into:
Energy function, which supplies material for the production of energy, which are agents of fats, carbohydrates and proteins.
Growth function, which involves the formation of new tissues, which are agents primarily proteins and some minerals.
Regulatory function, which promotes the proper use of plastic substances and energy.
All these substances are combined in an irregular manner in food. Some substances have more than one function, so for example, the proteins form tissues and are sources of energy and some minerals form tissues and have regulatory functions. The content of different nutrients depends role played by the different foods in the diet.
All the energy in our body comes from food and after processing gives rise to different types of energy. Thus we find the solar, heat, electricity, dynamics and potential. Food is a potential energy source used by the body. To be transformed by the living organism contain the energy released, which is used by different functions of the body.
How much energy is there in the foods?
The energy contained in food varies according to its composition.
The sugars and starches is given four calories per gram.
Fats give nine calories per gram.
Proteins, which are mainly used to form tissues, may also be used as an energy source and in this case, each gram of protein provides four calories.
The word "protein" comes from the Greek word "supremacy", that is of primary importance.
This term was suggested by Mulder, chemical Netherlands in the nineteenth century, to designate the universal component of all plant and animal tissues. The protein represents the most important substance in the organic realm. "Without protein there is no life on our planet. Through these occur the main phenomena of life."
It was designated a protein to a complex group of substances that have several properties in common and contain nitrogen, hydrogen, oxygen and carbon, and sometimes sulfur, phosphorus and other minerals. They are mainly used for the formation of tissues, hormones, enzymes and other substances essential for life, but can also burn the body to produce energy.
How are proteins formed?
Proteins are made up of less complex units called amino acids. To date 23 known different. Amino acids have been identified as nitrogenous compounds, with individual properties that the difference can be combined together to form a property almost limited protein.
Both the plant and the animal kingdom, each species forms its own proteins. Thus, wheat is not the same as the beans or the meat. Furthermore, within the same species there are many different proteins.
Plants can use nitrogen in the atmosphere to combine with other elements and forming their own amino acids and proteins. In general, animal proteins contain essential amino acids in greater quantities and proportions that man needs it and therefore are of greater nutritional value. Can be achieved, however, a situation similar to a balance of essential amino acids by appropriate combinations of vegetable proteins.
What roles do proteins play in the body?
After ingested proteins in the digestive tract suffer a process of simplification and division, and separate the different amino acids. These amino acids passing to the tissues and combine to form different types of proteins, which play different roles:
Join all tissues: muscle, nerve, bone, epithelial, connective, blood, etc..
Proteins are essential for the action undertaken by the vitamins and enzymes during the life processes that occur in all cells.
How much protein a person needs daily?
The amount of protein needed for living in health varies according to age, weight and physiological status of the individual. An adult needs about 1 gram of protein per kg of weight. A child has a much higher requirement. These differences are due to that during these special periods, there is increased formation of new tissues.