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The structure of dna
What is accomplished by dna replication
The structure of dna
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All living things on earth are made up of cells that contain DNA. Deoxyribonucleic acid or DNA is the genetic material of living things that can be found in the nucleus of the cells (Alcamo, 1996). It contains the genes and the genetic codes that contain the information that are essential for life’s functions which are passed from generations to generations. DNA composes of two polynucleotide chains twisted around each other in the form of a double helix. According to Alcamo (1996), each strand of the DNA double helix can act as a template for the synthesis of a new complementary strand as it contains a sequence of nucleotides that is exactly complementary to the nucleotide sequence of its partner strand. DNA replication is semi-conservative. Thus, two identical molecules of DNA are formed during DNA replication of one helix of DNA. Each new molecule of DNA contains one strand of parental DNA which is from the original helix and one strand of new DNA when DNA molecule is copied. DNA replication is a process that all cells must go through and occur before cell division (Corazon, 2010). There are several steps involve during DNA replication which are initiation, elongation, termination and proofreading and correction (refer to Figure 1 in Appendix 1).
Firstly, the process of DNA replication starts with initiation. The initiation refers to the process of unwinding of the DNA double helix. It occurs in the specific area of a chromosome known as the origins that contain a series of codes that attract helicase (Corazon, 2010). Bryant and Aves (2011) stated that “the initiation of DNA replication is important and highly regulated process in the cell division cycle” (p. 1119). In the process of DNA replication, some enzymes are involved s...
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References
Alcamo, E. (1996). DNA technology the awesome skill. Dubuque, IA: Wm. C. Brown.
Bank, E. (n.d.). The final product of the DNA replication process. Retrieved from http://education.seattlepi.com/final-product-dna-replication-process-4436.html
Bryant, J. A., & Aves, S. J. (2011). Initiation of DNA replication: Functional and evolutionary aspects. Annals of Botany, 107, 1119–1126.
Corazon, D. (2010). The DNA replication process: The steps involved in creating copies of deoxyribonucleic acid. Retrieved from http://www.brighthub.com/science/genetics/articles/65446.aspx
Meselson & Stahl, F. W. (1958). The replication of DNA in Escherichia coli. In Proceedings of the National Academy of Sciences (pp. 671-6820). USA.
Moses, R. E., & Summers, W. C. (Eds.). (1988). DNA replication and mutagenesis. Washington, DC, WA: American Society for Microbiology.
The purpose of this experiment is to identify an unknown insert DNA by using plasmid DNA as a vector to duplicate the unknown insert DNA. The bacteria will then be transformed by having it take in the plasmid DNA, which will allow us to identify our unknown insert as either the cat gene or the kan gene.
Upon completion of the experiment we were able to examine the DNA. First, the electrophorese
DNA is the genetic material found in cells of all living organisms. Human beings contain approximately one trillion cells (Aronson 9). DNA is a long strand in the shape of a double helix made up of small building blocks (Riley). The repeat segments are cut out of the DNA strand by a restrictive enzyme that acts like scissors and the resulting fragments are sorted out by electrophoresis (Saferstein 391).
DNA (Deoxyribonucleic acid) is a molecule found in in the nucleus of all cells in the body which carries our genetic information. DNA is found in the form of chromosomes, with a total of 23 pairs in the human body1. DNA holds the genetic coding for all our characteristics, i.e. our eye colour, body shape, and how we interact with others on a daily basis.
During interphase, cell growth, DNA replication, separation of centrioles and protein synthesis takes place. This phase is acknowledged to being the most extensive period of the cell cycle thus signifying the stage in which the cell devotes th...
“On February 21, 1953, Watson could see the finished structure, he had recognized how two pairs of complementary bases (adenine-thymine and guanine-cytosine) would have identical shapes if held together by hydrogen bonds, two long chains of such base pairs would likely form a double helix—roughly, the shape of an enormously long, winding, doubled-railed staircase. The DNA molecule, comprised of long strands of such base pairs in specific and varied sequences, could embed genetic information that, if the strands were separated, could be copied.”
1. DNA is a nucleic acid that carries the genetic information in the cell and is capable of self-replication and synthesis of RNA. DNA consists of two long chains of nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine. The sequence of nucleotides determines individual hereditary characteristics.
Precise chromosomal DNA replication during S phase of the cell cycle is a crucial factor in the proper maintenance of the genome from generation to generation. The current “once-per-cell-cycle” model of eukaryotic chromosome duplication describes a highly coordinated process by which temporally regulated replicon clusters are sequentially activated and subsequently united to form two semi-conserved copies of the genome. Replicon clusters, or replication domains, are comprised of individual replication units that are synchronously activated at predetermined points during S phase. Bi-directional replication within each replicon is initiated at periodic AT-rich origins along each chromosome. Origins are not characterized by any specific nucleotide sequence, but rather the spatial arrangement of origin replication complexes (ORCs). Given the duration of the S phase and replication fork rate, adjacent origins must be appropriately spaced to ensure the complete replication of each replicon. Chromatin arrangement by the nuclear matrix may be the underpinning factor responsible for ORC positioning. The six subunit ORC binds to origins of replication in an ATP-dependent manner during late telophase and early G1. In yeast, each replication domain simply contains a single ORC binding site. However, more complex origins are characterized by an initiation zone where DNA synthesis may begin at numerous locations. A single round of DNA synthesis at each activated origin is achieved by “lic...
Watson, J. D., Gilman, M., Witkowski, J., Zoller, M. (1992). Recombinant DNA. New York: W. H. Freeman and Company.
A chromosome is made up of two identical structures called chromatids. The process of nuclear division is called interphase; each DNA molecule in a nucleus makes an identical copy of itself. Each copy is contained in the chromatid and a characteristic narrow region called the centromere holds the two chromatids together. The centromere can be found anywhere along a chromosome but the position is the characteristic for a particular chromosome. Each Chromatid contains one DNA molecule. DNA is the molecule of inheritance and is made up of a series of genes. The fact that the two DNA molecules in the sister chromatids, and hence their genes, are identical is the key to precise nuclear division.
The birth of genetic engineering and recombinant DNA began in Stanford University, in the year 1970 (Hein). Biochemistry and medicine researchers were pursuing separate research pathways, yet these pathways converged to form what is now known as biotechnology (Hein). The biochemistry department was, at the time, focusing on an animal virus, and found a method of slicing DNA so cleanly that it would reform and go on to infect other cells. (Hein) The medical department focused on bacteria and developed a microscopic molecular messenger, that could not only carry a foreign “blueprint”, or message, but could also get the bacteria to read and copy the information. (Hein) One concept is needed to understand what happened at Stanford: how a bacterial “factory” turns “on” or “off”. (Hein) When a cell is dividing or producing a protein, it uses promoters (“on switches”) to start the process and terminators (“off switches”) to stop the process. (Hein) To form proteins, promoters and terminators are used to tell where the protein begins and where it ends. (Hein) In 1972 Herbert Boyer, a biochemist, provided Stanford with a bacterial enzyme called Eco R1. (Hein) This enzyme is used by bacteria to defend themselves against bacteriophages, or bacterial viruses. (Hein) The biochemistry department used this enzyme as a “molecular scalpel”, to cut a monkey virus called SV40. (Hein) What the Stanford researchers observed was that, when they did this, the virus reformed at the cleaved site in a circular manner. It later went on to infect other cells as if nothing had happened. (Hein) This proved that EcoR1 could cut the bonding sites on two different DNA strands, which could be combined using the “sticky ends” at the sites. (Hein). The contribution towards genetic engineering from the biochemistry department was the observations of EcoR1’s cleavage of
Discoveries in DNA, cell biology, evolution, and biotechnology have been among the major achievements in biology over the past 200 years, with accelerated discoveries and insight’s over the last 50 years. Consider the progress we have made in these areas of human knowledge. Present at least three of the discoveries you find to be the most important and describe their significance to society, health, and the culture of modern life. DNA (deoxyribonucleic acid) is a self-replicating molecule or material present in nearly all living organisms as the main constituent in chromosomes. It encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses.
Seidel, Jr., George E. "Cloning." World Book Student. World Book, 2014. Web. 13 Feb. 2014. source 19
Print. The. The "Polymerase Chain Reaction." Wikipedia. The World of the.
During this phase the DNA aka “deoxyribose nucleic acid” clone then forms chromatin. Chromatin is the mass of genetic material that forms into chromosomes. Interphase is divided into smaller parts: G1 Phase, S phase and G2 Phase. Throughout all the phases, the cells continuously develop by producing mitochondria, endoplasmic reticulum, and proteins. The actual division occurs during the S phase bur the G phases are mainly for the purpose of growing. Starting with the G1 phase the cell grows in preparation for certain intracellular components and DNA replication. This phase makes sure the cell is prepared for the process of DNA replication. It reviews the size and environment to ensure that is it ready to go, and cannot leave the G1 until it is complete. But what happens to a cell when it is not complete and cannot exit out of the phase? It will pause and transfer to phase G0. There’s no certain time to be in this phase but it will remain until it reaches the fitting size and is in a supportive surroundings for DNA replication. It will exit either G1 or G0 and there is no other way besides these. Then the cell will advance to the next phase which is the S phase. Synthesis, or more known as S phase is the section of the cell cycle when the DNA is wrapped into chromosomes then duplicated. This is a very important part of the cycle because it grants each of them that is created, to have the exact same genetic