Organelo is not a term accepted by the dictionary of the Royal Spanish Academy (RAE). However, as with many other concepts that are in the same situation, its use is quite frequent.
An organelle is what is known as an organelle, a unit that is part of a unicellular organism or a cell. These units fulfill various functions and confer a certain structure on the body in question.
Organelles, given these characteristics, are also called cellular elements. They are found within the cytoplasm and are more common in eukaryotic cells than in prokaryotes.
According to their origin, organelles can be classified in various ways. The autogenéticos organelles are created from an increase in the complexity of an existing structure. The endosymbiotic organelles, on the other hand, derive from the symbiosis that occurs with a different organism.
Among the different organelles that can be found in cells, the nucleus, mitochondria, ribosomes and endoplasmic reticulum stand out. It should be noted that not all organelles are present in all cells: their presence depends on the cell time and the organism.
Some organelles are specific to a certain class of organisms. The parentosome, for example, only appears in one type of fungus. The melanosome, on the other hand, is an organelle found in the cells of animals.
It should also be noted that the same organelles (such as nuclei or mitochondria) present different characteristics according to the organism.
Cell organelles
When talking about the membrane, we refer to the following elements:
* Cell wall: covers the cell and is made up of proteins and carbohydrates. It is found especially in plants and bacteria. It performs a defensive function of the external environment, and also helps to maintain the rigidity and shape of the cell;
* Plasma membrane: it is a structure of great elasticity and low thickness, a thin film of lipids that prevents the passage of certain substances between extracellular and intracellular fluids.
The cytoplasm is the largest cell structure. In 90% it is made up of water and within it there are various elements, each one also called organelle. Some of them are:
* glycocalyx: found only in eukaryotic animals. These are sugars bound to lipids or membrane proteins;
* microtubules: are responsible for intracellular transport;
* Golgi apparatus: it is a membranous organelle that is in charge of glycosylation and the secretion and maturation of proteins;
* mitochondria: only present in eukaryotes. It is involved in the production of ATP and in cellular respiration. It has an inner and an outer membrane, its own genetic material and respiratory enzymes;
* Endoplasmic reticulum: it is responsible for intracellular transport and is divided into smooth (it participates in the synthesis of lipids) and rough (it has ribosomes);
* ribosomes: they fulfill the function of protein synthesis and can be found in the rough endoplasmic reticulum.
The nucleus is the largest component within the cell and fulfills the following functions: it stores, transcribes and transmits the information that is stored in DNA, which is protected by proteins named histones . Within the nucleus is the nucleolus, with RNA and proteins; the latter help create new ribosomes.