Poly-merase chain reaction (PCR)
The two purines are known as adenine (A) and guanine (G), and the two pyrimides are thymine (T) and cytosine (C). The DNA strands appear as a double helix. They contain the genes and the genetic code which are passed from generations to generations. This is made possible through a process known as DNA Replication. DNA replication therefore, is an essential process in the perpetuation of the species.  The sequence of these bases, like … binary code for a computer, store information that codes for proteins on our bodies. Segments of DNA are called genes, and code for one protein. These segments of DNA are copied into another nucleic acid molecule called mRNA in a process known as transcription. mRNA is a single stranded molecules that is able to leave the nucleus and travel into the cytoplasm.  DNA, RNA and protein synthesis. The genetic material is stored in the form of DNA in most organisms. In humans, the nucleus of each cell contains 3 × 10 9 base pairs of DNA distributed over 23 pairs of chromosomes, and each cell has two copies of the genetic material. This is known collectively as the human genome. The mechanism of transcription has parallels in that of DNA replication. As with DNA replication, partial unwinding of the double helix must occur before transcription can take place, and it is the RNA polymerase enzymes that catalyze this process. Transcription is the process by which DNA is copied (transcribed) to mRNA, which carries the information needed for protein synthesis. Transcription takes place in two broad steps. First, pre-messenger RNA is formed, with the involvement of RNA polymerase enzymes. The mechanism of transcription has parallels in that of DNA replication. As with DNA replication, partial unwinding of the double helix must occur before transcription can take place, and it is the RNA polymerase enzymes that catalyze this process. 1 A molecule of a DNA polymerase binds to one strand of the DNA and begins moving along it in the 3' to 5' direction, using it as a template for assembling a leading strand of nucleotides and reforming a double helix. 2  In eukaryotes, this molecule is called DNA polymerase epsilon (ε). 1 A portion of the double helix is unwound by a helicase. 2  DNA replication can also be performed in vitro (artificially, outside a cell). DNA polymerases isolated from cells and artificial DNA primers can be used to initiate DNA synthesis at known sequences in a template DNA molecule. DNA polymerase has 5'-3' activity. All known DNA replication systems require a free 3' hydroxyl group before synthesis can be initiated (Important note: DNA is read in 3' to 5' direction whereas a new strand is synthesized in the 5' to 3' direction—this is often confused). DNA replication is the process of producing two identical replicas from one original DNA molecule. This biological process occurs in all living organisms and is the basis for biological inheritance. DNA polymerase has 5'-3' activity. All known DNA replication systems require a free 3' hydroxyl group before synthesis can be initiated (Important note: DNA is read in 3' to 5' direction whereas a new strand is synthesized in the 5' to 3' direction—this is often confused). Deoxyribonucleic acid (DNA) synthesis is a process by which copies of nucleic acid strands are made. In nature, DNA synthesis takes place in cells by a mechanism known as DNA replication. Using genetic engineering and enzyme chemistry, scientists have developed man-made methods for synthesizing DNA. The most important of these is poly-merase chain reaction (PCR). While the process of DNA replication was know before 1980, PCR was not possible because there were no known heat stable DNA polymerases. DNA polymerase is the enzyme that catalyzes the reactions involved in DNA synthesis. In the early 1980s, scientists found bacteria living around natural steam vents. The order in which the nucleotides are linked, called the sequence, is determined by a process known as DNA sequencing. In a eukaryotic cell, DNA synthesis occurs just prior to cell division through a process called replication. When replication begins the two strands of DNA are separated by a variety of enzymes. While the process of DNA replication was know before 1980, PCR was not possible because there were no known heat stable DNA polymerases. DNA polymerase is the enzyme that catalyzes the reactions involved in DNA synthesis. In the early 1980s, scientists found bacteria living around natural steam vents. DNA is made up of two strands and each strand of the original DNA molecule serves as a template for the production of the complementary strand, a process referred to as semiconservative replication. Cellular proofreading and error-checking mechanisms ensure near perfect fidelity for DNA replication. DNA polymerase has 5'-3' activity. All known DNA replication systems require a free 3' hydroxyl group before synthesis can be initiated (Important note: DNA is read in 3' to 5' direction whereas a new strand is synthesized in the 5' to 3' direction—this is often confused).
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DNA is synthesized through a process known as _____.