Deoxyribonucleic acid (DNA) is the hereditary material. It is a polynucleotide and is a double helix composed of two strand that run in opposite direction1. Each strand of DNA consist of a sugar molecule (deoxyribose), nitrogen base (adenine-A, guanine-G, thymine-T and cytosine-S) and a phosphate group. Adenine and guanine are double-ringed molecules known as purines while thymine and cytosine are single-ringed molecules known as pyrimidines1. Within the DNA molecule, the sugar molecules are joined to each other by 3’-5’ phosphodiester bonds where the 3’ carbon of a sugar molecule is connected to the 5’ carbon of the next sugar1. DNA is read from the 5’ end to the 3’ end where the 5’ end ends in a phosphate group while the 3’ end ends in a
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In both prokaryotes and eukaryotes, it is a complex multistep process that’s regulated by a variety of enzymes and proteins. Prokaryotic and eukaryotic DNA replication are both bi-directional processes, the DNA polymerases work from the 5’ to the 3’ end, they both involve leading and lagging strands and primers are required2. The main differences result from the difference in complexity between both types of organisms. While prokaryotic DNA is circular, eukaryotes have linear chromosomes with ends. In addition to that, eukaryotes have much more genetic material than prokaryotes which result in higher order packing arrangements of their DNA2. Prokaryotic DNA replication occurs in the cytoplasm and there’s a single origin of replication3. DNA polymerase III carries out both the initiation and elongation mechanisms, DNA polymerase I carries out DNA repair, gap fillings and removes RNA primers and, DNA gyrase is needed to relieve the strain when DNA is being unwound3. In prokaryotic DNA replication, Okazaki fragments are large, about 1000-2000 nucleotide long and the replication process is very rapid occurring at a rate of about 2000bp per second3. The schematic below shows DNA replication in
In both prokaryotes and eukaryotes, it is a complex multistep process that’s regulated by a variety of enzymes and proteins. Prokaryotic and eukaryotic DNA replication are both bi-directional processes, the DNA polymerases work from the 5’ to the 3’ end, they both involve leading and lagging strands and primers are required2. The main differences result from the difference in complexity between both types of organisms. While prokaryotic DNA is circular, eukaryotes have linear chromosomes with ends. In addition to that, eukaryotes have much more genetic material than prokaryotes which result in higher order packing arrangements of their DNA2. Prokaryotic DNA replication occurs in the cytoplasm and there’s a single origin of replication3. DNA polymerase III carries out both the initiation and elongation mechanisms, DNA polymerase I carries out DNA repair, gap fillings and removes RNA primers and, DNA gyrase is needed to relieve the strain when DNA is being unwound3. In prokaryotic DNA replication, Okazaki fragments are large, about 1000-2000 nucleotide long and the replication process is very rapid occurring at a rate of about 2000bp per second3. The schematic below shows DNA replication in