The RNA or Protein: Which Was First? Essay Example

While many theories exist that attempt to explain whether DNA, RNA, or protein came first, there is clear evidence that RNA was the first nucleic acid and that it gave rise to protein after a period of evolution. According to humanity’s first understanding of central dogma, DNA is necessary for the creation of RNA, which is necessary for the creation of protein. However, more recent scientific explorations have uncovered that this order is not always conserved. For example, reverse transcription creates DNA from RNA. This knowledge demonstrates that RNA is the only molecule that is able to create both DNA and protein, which is rare in biology. Therefore, it is reasonable to state that RNA came first.

Additional evidence for RNA existing first is that unlike DNA, it can function as an enzyme. In the human body, enzymes are capable of catalyzing chemical reactions in the same manner that proteins are conventionally able to accomplish. This indicates that in primitive organisms, it is possible that RNA was the major molecule of the cell, as it functioned as both a means by which the genetic code can be stored in addition to providing the means by which metabolism can be carried out. Under these circumstances, it would not be necessary for a cell to contain either DNA or protein to survive.

These observations have been backed by a theory known as the RNA-world hypothesis, in which scientists claim that since RNA has the potential to be a self-replicating molecule, the current life on earth had descended from this “RNA world”. The theory is backed up by the evidence discussed above stating that RNA is necessary for the creation of protein and that it is capable of serving as an enzyme. However, it is also important to consider that science has uncovered many different types of RNA with a variety of different functions. This includes the ability to silence portions of DNA, create proteins, and lengthen nucleic acids. Therefore, RNA has the ability to facilitate many of the activities that are necessary for life.

The properties of RNA compared to the properties of DNA and protein also support the belief that RNA came first. Most importantly, RNA is typically single stranded, but has the ability to bind with other RNA strands or itself, which emphasizes its versatility. It is therefore able to change into many conformations that can potentially dictate its function. Meanwhile, DNA is highly stable and rigid, and remains in a double helix shape when it is not undergoing replication. It is therefore unable to achieve many of the functions that RNA can, although this structure and stability allows it to be an effective storage molecule. When one looks at the structure of protein, it appears that proteins mimic the versatility of RNA, but either RNA or a like chemical reaction that triggers the polymerization of amino acids is necessary to create it. Therefore, it seems that DNA and protein share traits that RNA has, but RNA is capable of accomplishing more of the functions needed for life.

In conclusion, it is likely that RNA came before DNA and protein due to the versatility of the molecule. Since it is able to store genetic information and function as an enzyme, it is likely that this is the only molecule that early life needed to survive. As organisms became more complex throughout evolution, RNA facilitated the creation of DNA and protein to allow the cell to have more specialized functions. However, RNA remains a necessary component for life today and it is unlikely that we would be able to survive without it. Therefore, a majority of scientists agree that RNA is what came first.