Organic Matter – Concept, types, characteristics and examples

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

Organic matter - wood
When we talk about organic matter, we mean that which is linked to life.

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 “carbon chemistry.” Thus, when we speak of organic matter we refer to that which is linked to life: that which 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 decomposing 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 greatest presence of organic matter.

Types of organic matter

Organic matter is generally made up 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, accumulations of carbohydrates that make up dense, hydrophobic molecules.
  • Sugars Carbohydrates or saccharides are known by this generic name, that is, molecules of carbon, hydrogen and oxygen that are the basic biological forms of energy.

Soil organic matter

Fresh organic matter
Fresh organic matter is made up of plant debris and household waste.

Soil organic matter It is the product of the various life cycles of living beings, whose bodies release waste and substances that, when decomposed, make up 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. Relatively recent plant remains and household waste, with a high sugar content and a high energy value.
  • Partially decomposed organic matter. Although in a state of decomposition, this matter provides an important organic and nutrient content to soils, acting as compost or fertilizer.
  • Decomposed organic matter. That which takes a long time to decompose and does not contain too many nutrients, but provides support for the absorption of water in the soils.

Importance of organic matter

The presence of decomposing organic matter is extremely important in soils, as has been seen, not only to supply nutrients and usable material to plants, fungi or other plant organisms, as fertilizer, but also modify the physicochemical properties of the soil, allowing it to retain more water, and avoiding 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 for heterotrophic organismsLike human beings themselves, we can keep our metabolisms going, since we cannot synthesize the substances that we require like plants. Therefore, all heterotrophs feed on organic matter from the bodies of other animals and plants.

Examples of organic matter

Organic matter - silk
Silk is secreted by the caterpillars of certain butterflies when they weave protein substances.

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 sheets of cellulose with lignin.
  • The silk secreted by 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.

Inorganic material

Inorganic matter is that which it is not a product of life’s own chemical reactions, but obeys 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 beings, inorganic matter is due to electromagnetic processes, known as ionic bonds or metallic bonds.

Differences between organic and inorganic matter

Cotton - organic matter
Organic matter can be decomposed by the action of biological mechanisms.

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, this being its fundamental element. The inorganic, on the other hand, presents various other elements in its place.
  • Organic matter is biodegradable, that is, it can decompose through biological mechanisms or simple deterioration, reducing itself to its basic elements. Not so inorganic, which depends on electromagnetic (ionic) attraction.
  • Inorganic matter is generally non-combustible and non-volatile, while the main known fuels are of organic origin, such as oil.
  • Organic matter can present isomerism (molecules of the same constitution but different physical-chemical properties, due to a different orientation of the atoms), while inorganic matter generally does not.