Different Types of Cells
Cells, even though they are the most basic unit of life, contain such an extraordinary complex structure within them that allows them and other organisms to function in perfection. Cells are usually classified by the nucleus. There exist the eukaryotes, which are the type of cells containing a nucleus and there are also the prokaryotes, which are the type of cells containing no nucleus. Prokaryotes (normally bacteria) are the most abundant organisms here on earth, however, in this essay I will focus on describing eukaryotes, for they conform our body and once understanding these types of cells, which are very complex, it will be easier to understand prokaryotes.
Eukaryotes are protected by a membrane, called the Plasma Membrane. Inside of this membrane, they have an endomembrane system with organelles that carry out different jobs in the cell to keep it alive and working. One of the most important or maybe the most relevant organelle within the eukaryotes is the Mitochondrion or Mitochondria in plural. These can be called the power plants of the cell, for they carry out the respiration process within the cell and breakdown sugars in order to convert them to a substance called Adenosine Triphosphate or ATP for short. This is the main substance of energy within a cell that allows proteins to move in the cell. Therefore, some scientists believe that the mitochondria are the ones that enable eukaryotes to be what they are.
As I have mentioned before, eukaryotes have this name because part of their internal structure contains a nucleus. The nucleus is what defines the cell, because in it reside chromosomes like the DNA and other proteins. Outside of the nucleus are found the ribosomes that are a type of sugar that contributes to the construction of proteins within a cell.
Then, there is the Endoplasmic Reticulum which can be rough, meaning it contains ribosomes, or smooth, for it doesn’t contain ribosomes. Either way, the Endoplasmic Reticulum (E.R.) helps the cell in the creation of proteins inside the plasma membrane. From the E.R. proteins can travel to the Golgi apparatus that packages proteins and sends them out to the parts of the cell that require them. The Golgi apparatus can package the proteins in empty chambers called vesicles. Some vesicles are Lysosomes that are packed with enzymes made of proteins used to digest unnecessary material like proteins that are no longer needed and maybe even pathogens.
There are also other vesicles called the Peroxisomes, also made of proteins, which break down fats and neutralize toxins. Out of their process, however, hydrogen peroxide, which can be toxic for the cell, is created. As I wrote earlier, though, cells are made to work perfectly and the peroxisome has the capability to transform this substance (hydrogen peroxide) into water.
Next is the cytoskeleton that contains special organelles that help give the cell its shape, like microtubules. These tubules are like rods of proteins where vesicles can travel in, for they form like a path. Microtubules grow out of the Centrosome that contains bundles of tubes known as Centrioles and they form the skeleton and roads of the cell.
Anyway, there are so many organelles and functions within a cell, you could probably write a whole book describing them, and here I just presented the basics to let you understand two ways cells can be identified. As you can probably see, proteins form a really big part of the cell, without them, the cell would eventually end up dying. Just as the owning of a nucleus can define the type of a cell (if it is prokaryote or eukaryote), so also the production and usage of proteins within a cell can tell us if it is a cell in the muscles of our hands or a cell in our lungs. One will use proteins to send out signals to the brain that will tell us we need oxygen and give the lungs the capability to expand and absorb the oxygen into our blood system. Lung cells will probably produce and use more proteins constantly, because we need to breathe all the time. On the other hand, the cells in the muscles, nerves, and everything that makes our hands will need to use less lysosome, for example, when we move them.
If you want to read more about the forces that help a cell move you can click here.