What is organic matter?

We explain what organic matter is and how it is classified. In addition, its importance, examples and differences with inorganic matter.

1. What is organic matter?

Organic matter is all that chemically composed around carbon as its fundamental atoms , which is why organic chemistry is known as the “carbon chemistry”. Thus, when we talk about organic matter we mean the one that is linked to life : the one that makes up the bodies of living beings , as well as most of their substances and waste materials.

At the same time, in geological terms, organic matter constitutes the first layer of the soil , composed of decaying remains of living beings, such as plants, animals and waste that provide various nutrients to producing organisms, such as vegetation. The most fertile soils are precisely those with the highest presence of organic matter.

2. Types of organic matter

Organic matter generally consists of:

• Proteins . Linear chains of amino acids that form macromolecules with determined physicochemical properties, according to their complexity.
• Lipids . Various types of fats, that is, carbohydrate accumulations that make up hydrophobic and dense molecules.
• Sugars By this generic name, carbohydrates or saccharides are known, that is, carbon, hydrogen and oxygen molecules that are the basic biological forms of energy.

3. Soil organic matter

The organic matter of the soil is the product of the various life cycles of living beings , whose bodies release waste and substances that, when decomposed, form a diverse mass, rich in nutrients and highly usable by autotrophic organisms such as plants.

Three types of organic matter are usually distinguished in relation to the constitution of soils:

• Fresh organic matter Remains of relatively recent plants and household waste, with a high sugar content and a high energy value.
• Organic matter partially decomposed. Although in a state of decomposition, this matter provides an important organic and nutrient content to the soil, making compost or fertilizer.
• Decomposed organic matter. The one that has a long time of decomposition and does not contain too many nutrients, but provides support for the absorption of water in the soil.

4. Importance of organic matter

The presence of decomposing organic matter is of the utmost importance in soils, as has been seen, not only to supply nutrients, plants and fungi with other materials, as a fertilizer, but also modify the properties physical-chemical soil , allowing it to retain more water, and preventing its degradation by operating as a pH buffer , as well as preventing violent temperature fluctuations in it.

On the other hand, organic matter is necessary so that heterotrophic organisms , such as humans themselves , can keep our metabolisms going , since we cannot synthesize the substances we require such as plants. Therefore, all heterotrophs feed on the organic matter of the bodies of other animals and plants.

5. Examples of organic matter

Some common examples of organic compounds are:

• Benzene and other hydrocarbons such as natural gas or oil and its derivatives, such as gasoline.
• Structural sugars such as cellulose from plants, which serves as a material to form starches (such as cotton) or to form fruits.
• The wood of the trees is a kind of resin formed gradually throughout the life of the plant, and which is made up of various cellulose sheets with lignin.
• The silk that secretes the caterpillars of certain butterflies, weaving secreted protein substances when the moment of metamorphosis has arrived.
• The bones of dead animals, even those of the human being himself.
• The defecations of animals, whether herbivores, carnivores or omnivores.

6. Inorganic material

Inorganic matter is that which is not the product of life’s own chemical reactions , but is due to the logic of ionic and electromagnetic attraction. This does not mean that they are substances totally foreign to living beings, since many of them are present in their bodies or serve as a food substrate.

While organic matter is formed due to processes linked to living things, inorganic is due to electromagnetic processes, known as ionic bonds or metal bonds .

7. Differences between organic and inorganic matter

The differences between organic and inorganic matter can be summarized as follows:

• The essential: organic matter is generated by living beings, while inorganic is formed due to natural reactions in which life does not intervene.
• Organic matter is chemically composed around carbon atoms , which is its fundamental element. Inorganic, on the other hand, presents various other elements in its place.
• Organic matter is biodegradable, that is, it can be decomposed by the action of biological mechanisms or by simple deterioration, reduced to its basic elements. Not so inorganic, which depends on electromagnetic (ionic) attraction.
• Inorganic matter is generally incombustible and non-volatile, while the main known fuels are of organic origin, such as oil.
• Organic matter may have isomerism (molecules of equal constitution but different physical-chemical properties, due to a different orientation of atoms), while inorganic matter generally does not.