A nutrient is what nourishes , that is to say, which increases the substance of the animal or plant body . These are chemicals that come from outside the cell and that it requires to be able to develop its vital functions. Nutrients are absorbed by the cell and transformed through a metabolic process of biosynthesis (known as anabolism ) or by degradation, to obtain other molecules .
Among the various substances that make up food, nutrients are those that actively participate in metabolic reactions. The water, the oxygen and minerals are the basic nutrients that plants consume, while humans and animals feed on vegetables and other animals.
The vitamins, proteins, lipids and carbohydrates are some of the substances that are part of the nutrients consumed by all living beings that do not have photosynthetic capacity (that is, they are not plants).
According to their function In metabolic reactions, nutrients can be classified into two large groups: essential nutrients (vital for the organism since it cannot synthesize them, but obtains them from the environment) and nonessential nutrients (They are not vital and, in certain cases, can be synthesized by precursor molecules).
Another classification of nutrients can be done according to the volume in which the cells consume them. The macronutrients are necessary in large daily amounts (such as proteins) and constitute the basis of the diet. The micronutrients On the other hand, they are required in small quantities and usually act as regulators of energy processes.
The path taken by the essential substances for life, both for the physical and biological environment, is known as nutrient cycle and is considered a fundamental concept for the ecology. Among the essential cycles are carbon, oxygen, nitrogen and water. There are many more compounds and elements of vital importance, although in considerably smaller quantities.
Here are two of the most significant cycles for the life of the Planet:
* carbon cycle: these are the different stages in which the ecosystem Earth uses carbon. Basically, it begins at the moment in which the plants take advantage of the carbon dioxide in the atmosphere, or present in the water in a state of dissolution, through the process of photosynthesis. A percentage of this carbon is integrated into plant tissues such as carbohydrates, proteins and fats; The rest is returned to its place of origin through breathing. In this way, herbivorous animals consume it while feeding, and then reorganize and degrade their compounds. One part is released by breathing, and another is stored in the tissues, which will then be ingested by carnivorous animals. In all cases, carbon breaks down and is released in the form of carbon dioxide, which plants use to restart the cycle;
* water cycle: all aquatic portions of the Earth are constantly modified, but the amount is always the same. First, the ocean surface evaporates and begins to rise. During its upward journey, steam cooling occurs, which makes it Water condensed, which results in cloud formation. Depending on the temperature of the atmosphere, the water rushes in the form of snow or rain, thus returning to the Planet. Once on the surface, one part will be consumed by living beings, while the rest will be divided between soil and water bodies, such as rivers and oceans.