Replication, transcription, and translation are the three processes in DNA, RNA, and protein synthesis that create the variety of life found on earth. Replication is the process by which DNA makes an exact copy of itself in preparation for cell division (VCBio, 2011). Each pair of DNA has 23 pairs of chromosomes and each cell has two copies of the genetic material (ATDBio, 2016). The following describes the process by which replication, transcription, and translation occur.
Each strand of DNA consists of four different nucleotides: adenine, thymine, cytosine, and guanine. Each only pairs with one another nucleotide. Adenine always pairs with thymine and cytosine always pairs with guanine. There are 64 possible codons designated by three letter combinations. The cell division process begins when the strand of DNA unzips itself, providing a template to produce the complementary strand of DNA (ATDBio, 2016). The process begins when an RNA polymerase binds to one of many sites on the DNA (VCBio, 2011). The sites on the DNA are known as promoter regions and can be recognized by their unique nucleotide sequence. Sometimes mistakes occur in the replication process. The DNA has repair enzymes that can correct the mistake, but sometimes these mistakes survive and are incorporated into the genome (ATDBio, 2016). The replication process results in DNA that makes an exact copy of itself. Replication occurs during the synthesis phase of cell division (VCBio, 2011).
The purpose of replication and transcription are different. With replication, the purpose is to preserve the entire genome for the next generation. With transcription, the copy that is made is for the purpose of biochemical processes. With replication, one strand of mother DNA becomes too daughter strands. With transcription, there are many different products such as, mRNA, tRNA, and different other forms of RNA (VCBio, 2011).
Transcription is the process by which DNA is copied during protein synthesis. This involves the production of a prototype of messenger RNA (mRNA) that is then edited to produce the mRNA molecule (ATDBio, 2016). There are many different types of mRNA, each of which encodes for a certain protein. There are hundreds in each cell. Bacteria and viruses are some of the most efficient at the replication, transcription, and translation processes (Robinson and van Oijen, 2013). A virus, such as HIV inserts itself during the transcription process of the gene. Some viruses, such as HIV, are only nine genes long, but these genes have all of the information to produce the structural components of the disease (Sullivan, 2015).
Translation occurs when the mRNA formed in the transcription process is transported out of the nucleus and into the cytoplasm of the cell. It is here that the mRNA directs protein synthesis and creates amino acids (VCBio, 2011). In this process, the ribosomes (rRNA) bind to a single strand mRNA chain, which contains a mirror of the DNA template. Transporter RNA (tRNA) carry amino acids that coupled to the ribosomes to form a polypeptide (VCBio, 2011). The genetic code of the mRNA determines the amino acid that will be formed by the process. It might be noted that some amino acids have more than one codon that can produce it (VCBio, 2011). Species are selective as to which ones they choose (VCBio, 2011).
Chemical agents, damage from the sun, cigarette smoke, radiation, and other environmental influences can cause a mistake in the replication, transcription, and translation processes. If these mutations survive, they can be passed down to future generations and become part of the genetic code (ATDBio, 2016). These errors in the copying process produce diseases such as cancer, rheumatoid arthritis, and other diseases that have become a part of the species. The stability of the species depends on the accuracy of the replication and transcription processes.
- ATDBio. (2016). Transcription, Translation, and Replication. Retrieved from http://www.atdbio.com/content/14/Transcription-Translation-and-Replication
- Robinson, A. & van Oijen, A. (2013). Bacterial replication, transcription and translation: mechanistic insights from single-molecule biochemical studies. 11:303-315.
- Sullivan, J. (2015). Integration of Viral DNA. Cells Alive. Retrieved from http://www.cellsalive.com/hiv3.htm
- VCBio. Replication/Transcription/Translation. Retrieved from http://www.vcbio.science.ru.nl/en/virtuallessons/cellcycle/trans/