The notion of biogenesis is used in the field of biology to name the principle that indicates that a living organism always comes from another living organism. The term also refers to the manufacture and processing of chemicals that living things develop.
Biogenesis, therefore, can refer to the process that leads to the “production” of a new living organism. A hen can lay an egg, from which a new hen hatches. In turn, this second hen also generates other specimens through its own eggs. This is known as biogenesis – the birth of a living being from another living being.
The theory of biogenesis indicates that a life can only be generated from a pre-existing life. In other words: life never comes from inorganic elements. The smallest and simplest visible unit that possesses independent life is the cell.
Continuing with these ideas, it can be pointed out that biogenesis maintains that there is no spontaneous generation of life starting from substances that are not alive. The opposite position is the one wielded by the theory of spontaneous generation, which proposes the emergence of plants and animals from mud or the remains of organisms that at some point had life, for example.
The theory of spontaneous generation was dominant until the middle of the seventeenth century, when it began to be shown that even microorganisms did not arise spontaneously, but that they always came from another living being. Thus, biogenesis ended up imposing itself as a principle to explain the origin of life.
It is known by the name of mitochondrial biogenesis to a highly regulated process that requires the use of nuclear DNA to encode mitochondrial proteins, due to the low amount of proteins encoded by mitochondrial DNA. As a data of interest, there is a greater relationship between mitochondrial biogenesis and resistance exercise than with resistance exercise.
A question that may arise when faced with this issue is how coordinated regulation is achieved, since the location of the genes necessary for it is not the same for everyone. The answer to this question is based on the presence of molecules that work by sending messages between each compartment. According to a study carried out in 2009, the fundamental steps of this process are the following:
* the signaling reactions induced by physical exercise are activated;
* transcription factors and co-activating proteins are activated;
* the nuclear genes responsible for coding are regulated;
* mitochondrial RNA transcripts are stabilized and translated into protein precursors;
* the precursors are transported within the relevant compartments;
* mitochondrial DNA is expressed;
* Gene products, both mitochondrial and nuclear, are assembled in complexes with various subunits within the reticulum.
Although there are more regulators of mitochondrial biogenesis, among those known to date, the transcriptional coactivator PGC-1α, and the transcription factors NRF-1, NRF-2 and Tfam stand out. In short, a transcription factor is a protein with the ability to bind to DNA in a certain area to regulate transcription, either through its activation or inhibition.
Transcriptional coactivators, for their part, are also proteins, although they work indirectly, that is, they do not bind to DNA. Its role is that of an indispensable intermediary for the beginning of the transcription process, since it communicates the molecules and factors involved. These two classes of proteins work together with others to get RNA polymerase to do its job.