There are close to one hundred billion cells in our body. They are very small and there are different kinds. They group together to form tissues, which then form organs and systems.
In order to do its job, the cell has a few essential components within. They are chemical substances and enzymes that react to provide the cell with energy.
In addition, it has genetic material, which contains the information needed to produce other cellular components and cell duplication.
Depending on their structure, size and function, cells can be split into two large groups:
– Prokaryotes: they do not have a nucleus. Their structure is simpler than eukaryotes because they only have ribosomes, chemical elements and enzymes within their cytoplasm, all of which are necessary for growth and cell division. These cells are believed to be the first kind of cell present on the planet.
– Eukaryotes (animals and plants): They have a nucleus, are larger than prokaryotes and are found in the human body. Their internal arrangement is more evolved and complex; genetic material is contained within the nucleus, which is surrounded by nucleoplasm and protected with its own membrane. It can perform specific tasks, such as coordinating cellular chemistry, meaning, internal reactions and metabolism through the activation of cellular organelles.
Well organized cells
Even though they are very small, cells have a basic, well organized structure. They all have protoplasm, which is cytoplasm plus the cell nucleus. Cytoplasm, which includes the entire volume of the cell except for the nucleus, is the medium in which the cell’s chemical changes and metabolic reactions take place. It is made up of an aqueous solution called cytosol, which groups together a vast amount of specialized structures and cellular organelles.
The most important organelle is the nucleus, which is formed by a double membrane. Within is the nucleolus (it is involved in the creation of ribosomal subunits) and the genetic material.
In addition, in order to communicate with the cytoplasm, the nucleus has openings in its membrane walls known as nuclear pores.
