This is performed by an enzyme known as DNA helicase. In order to unwind DNA, these interactions between base pairs must be broken. Adenine only pairs with thymine and cytosine only binds with guanine. DNA has four bases called adenine (A), thymine (T), cytosine (C) and guanine (G) that form pairs between the two strands. Science Photo Library / Getty Images Step 1: Replication Fork Formationīefore DNA can be replicated, the double stranded molecule must be “unzipped” into two single strands. Prior to DNA replication, the chromatin loosens giving cell replication machinery access to the DNA strands. Chromatin condenses to form chromosomes during cell division. In order to fit within the nucleus, DNA is packed into tightly coiled structures called chromatin. This twisting allows DNA to be more compact. Double-stranded DNA consists of two spiral nucleic acid chains that are twisted into a double helix shape. It consists of a 5-carbon deoxyribose sugar, a phosphate, and a nitrogenous base. It is also vital in the cell repair process.ĭNA or deoxyribonucleic acid is a type of molecule known as a nucleic acid. The overall DNA replication process is extremely important for both cell growth and reproduction in organisms.Enzymes are vital to DNA replication since they catalyze very important steps in the process.Replication involves the production of identical helices of DNA from one double-stranded molecule of DNA.The process that copies DNA is called replication. Since DNA contains the genetic material for an organism, it is important that it be copied when a cell divides into daughter cells.Deoxyribonucleic acid, commonly known as DNA, is a nucleic acid that has three main components: a deoxyribose sugar, a phosphate, and a nitrogenous base.Following replication the new DNA automatically winds up into a double helix.This is why DNA replication is described as semi-conservative, half of the chain is part of the original DNA molecule, half is brand new. The result of DNA replication is two DNA molecules consisting of one new and one old chain of nucleotides.Finally, an enzyme called DNA ligase seals up the sequence of DNA into two continuous double strands.The new strand is proofread to make sure there are no mistakes in the new DNA sequence.The gaps where the primer(s) were are then filled by yet more complementary nucleotides. Once all of the bases are matched up (A with T, C with G), an enzyme called exonuclease strips away the primer(s).
0 Comments
Leave a Reply. |