more complex about dnaB gen and helicase?
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The function of DnaB helicase is to couple ATP hydrolysis with the unwinding of the DNA double helix at the replication fork, creating two antiparallel strands of ssDNA. DNA polymerase and DnaB helicase are complexed via the tao subunit of DNA polymerase which serves to stabilize the hexameric structure of the helicase. This now immobilized protein complex allows for DNA to pass through it. There are other helicases involved with replication but this is the only one found to be essential (knockout mutations are fatal) and the only one that can stimulate primase. If you need more info, please formulate a somewhat more coherent and specific question.
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Experimentally you can do primer extension, which will show the +1 site, from there you can identify the RBS and -10 and -35 sequences.\n\nYou can also do mobility shift assays with RNA polymerase to show that a certain piece of DNA contains the promoter, then do DNAse protection assays to show where the polymerase is actually binding.
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you can read up on it here\n\nhttp://en.wikipedia.org/wiki/DNA\n\nbut even better would be to buy related books and take related courses
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I think what you're looking for has to do with replication. Every time the cell goes through mitosis to divide, it has to make an exact copy of all the DNA in the cell, so that there are two complete copies, one for each daughter cell. The process of replication and division is the cell cycle.\n\nIn replication, a complex of enzymes copies the DNA by unzipping the double helix to expose the single strands. Someone else mentioned A-T C-G bair pairing and that is correct. The four subunits in DNA are the bases, and they are abbreviated A,T,C and G. Just by the shape of the molecules, A will connect with T and C with G pretty much always (though there are exceptions that are beyond the scope of a general explanation). \n\nSo in replication, enzymes pull the two strands of the double helix apart in short regions, pulling apart the A-T C-G bair pairing. It is energetically unfavorable to have a single strand of DNA exposed and not base paired. Free nucleotides in the cell will come in and form hydrogen bonds with the exposed template strand (it will happen on both strands), and then enzymes will connect the newly deposited bases with phosphodiester linkages to form a new DNA molecule. This forms a new strand of what is called duplex DNA, meaning it is a new double helix. The complementarity of the base pairs drives replication to produce an exact copy of each part of the genetic code. The error rate is very low, but errors can and do occur, and there is proofreading machinery to check for mistakes and excise and replace incorrect base pairs.\n\nPictures are helpful...in the second link, scroll down to see the replication bubble. A replication fork and a replication bubble are essentially the same thing...it's the site where the double helix is open and replication is occurring.
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Good God man you are on the net, you have more information than you know what to do with right at your finger tips. Go to Yahoo's main page and type genetics into the search bar.
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Nearly Complete Genomic Libraries of Higher Organisms Can Be Prepared by λ Cloning\n\nWith the availability of λ phage cloning vectors, preparation of genomic libraries for higher organisms, including humans, is feasible. A genomic library is a set of λ (or plasmid) clones that collectively contain every DNA sequence in the genome of a particular organism. Figure 7-12 summarizes the general procedure for constructing a λ genomic library. The λ DNA first is treated with a restriction enzyme to produce fragments called λ vector arms, which have sticky ends and together contain all the genes necessary for lytic growth. This step frees the nonessential region in the middle of the λ genome; this region is separated from the λ arms and discarded. Genomic DNA then is extracted from a cell type that contains all the genetic information of the organism under study. Sperm cells or cells of an early embryo often are used as sources of mammalian DNA. The extracted DNA then is cleaved by a restriction enzyme to produce ≈20-kb fragments with sticky ends complementary to the sticky ends on the λ vector arms being used.\n\nThe λ arms and the collection of genomic DNA fragments are mixed in about equal amounts. The complementary sticky ends on the fragments and λ arms hybridize and then are joined covalently by DNA ligase. Each of the resulting recombinant DNA molecules contains a foreign DNA fragment located between the two arms of the λ vector DNA. The ligated recombinant DNAs then are packaged into λ virions in vitro as described above. Only DNA molecules of the correct size can be packaged to produce fully infectious recombinant λ virions.\n\nFinally, the recombinant λ virions are plated on a lawn of E. coli cells to generate a large number of recombinant λ plaques. Since each plaque arises from a single recombinant virion, all the progeny λ phages that develop are genetically identical and constitute a clone carrying a particular genomic DNA insert. The different plaques correspond to distinct phage clones, each carrying a different DNA insert, and collectively they constitute a λ genomic library. Multiple λ vectors have been constructed containing different restriction sites, so that restriction fragments generated by a variety of restriction enzymes can be cloned in λ vectors.\n\nIn constructing a library of genomic DNA, the DNA commonly is cleaved with a restriction enzyme that recognizes a 4-bp restriction site (e.g., Sau3A, as shown in Figure 7-12). A specific 4-bp sequence will occur on average once every 44 = 256 base pairs. Complete digestion of the human haploid genome, which contains ≈3 × 109 base pairs, would yield somewhat more than 107 nonoverlapping different fragments. However, to increase the probability that all regions of the genome are successfully cloned and represented in the λ genomic library, the genomic DNA usually is only partially digested to yield overlapping restriction fragments of ≈20 kb (Figure 7-13). In a large λ library constructed from such overlapping restriction fragments, a specific sequence of genomic DNA (e.g., the gene encoding β-globin) often is contained in or extends over several “overlapping” clones. By a technique called chromosome walking, described in the next chapter, overlapping genomic clones can be ordered.\n\nThe size of a genomic library for a given organism depends on the amount of DNA in that organism's haploid genome. If the human genome of about 3 × 109 base pairs is cleaved into 20-kb fragments for insertion into a λ vector, then roughly 1.5 × 105 different recombinant λ phage virions would be required to constitute a complete library. Because the restriction fragments of human DNA are incorporated into phages randomly, about 106 recombinant phages are necessary to assure that each region of human DNA has a 90 – 95 percent chance of being included.\n\nEach plaque produced by a recombinant bacteriophage λ contains large numbers of recombi
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well, hope these help:\n\nhttp://www.bbc.co.uk/dna/h2g2/A388217\n\nhttp://www.chemistrysurvival.com/
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The four nucleotide bases, the building blocks of every piece of DNA, are represented by the letters A, C, G, and T, which stand for their chemical names: adenine, cytosine, guanine, and thymine. The A on one strand always pairs with the T on the other, whereas C always pairs with G. The two strands are said to be complementary to each other. \n\nTo copy DNA, polymerase requires two other components: a supply of the four nucleotide bases and something called a primer. DNA polymerases, whether from humans, bacteria, or viruses, cannot copy a chain of DNA without a short sequence of nucleotides to "prime" the process, or get it started. So the cell has another enzyme called a primase that actually makes the first few nucleotides of the copy. This stretch of DNA is called a primer. Once the primer is made, the polymerase can take over making the rest of the new chain. \n\nA PCR vial contains all the necessary components for DNA duplication: a piece of DNA, large quantities of the four nucleotides, large quantities of the primer sequence, and DNA polymerase. The polymerase is the Taq polymerase, named for Thermus aquaticus, from which it was isolated. \n\nThe three parts of the polymerase chain reaction are carried out in the same vial, but at different temperatures. The first part of the process separates the two DNA chains in the double helix. This is done simply by heating the vial to 90-75 degrees centigrade (about 165 degrees Fahrenheit) for 30 seconds. \n\nBut the primers cannot bind to the DNA strands at such a high temperature, so the vial is cooled to 55 degrees C. At this temperature, the primers bind or "anneal" to the ends of the DNA strands. This takes about 20 seconds. \n\nThe final step of the reaction is to make a complete copy of the templates. Since the Taq polymerase works best at around 75 degrees C (the temperature of the hot springs where the bacterium was discovered), the temperature of the vial is raised. \n\nThe Taq polymerase begins adding nucleotides to the primer and eventually makes a complementary copy of the template. If the template contains an A nucleotide, the enzyme adds on a T nucleotide to the primer. If the template contains a G, it adds a C to the new chain, and so on to the end of the DNA strand. This completes one PCR cycle.  \n\nIf Instead of G if A gets added to C, then its called as mismatch...or mutation which DNA come over by repair mechanism...\n\nhope this helps!!!
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http://www.dnaftb.org/dnaftb/\n\nThis site has animations to help you .Also use www.brainpop.com \nEn.wikipedia.com also helps\n\nBest regards,\nSidra
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In 1869 Friedrich Miescher, a Swiss researcher, stained a cell nucleus with bromine I think, and found that something in it would stain.  He extracted this something and determined that It was composed of phosphoric acid, nitrogenated organic bases and sugar.\n\nIn 1943 Oswald Avery, a Canadian researcher found that bacteria would transform when washed, when exposed to protease, but not when exposed to deoxyribonuclease.  This led him to conclude that the something Miescher found was by composition supposed to be called deoxyrybonucleic acid and that this DNA was in fact the basic unit of heredity because doexyribonuclease is an enzyme that eats up DNA.\n\nThat's the evidence.\n\nOut genomes aren't made of RNA because that is a single stranded chain. Nothing wrong with that, but it's less sturdy than DNA, which is double stranded and supercoiled and so on.  It's a matter of what is the better means of storing your genetic information.
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I can definitely tell you the enzyme is not an initiator. The DNA polymerase has a sequence that initiates replication. \n\nThe protein you are talking about is called SSB (Single Starnd Binding) protein. I am very amazed where you got this question from. I have never before heard such a function related name for SSB protein. But if it is a must, I would go for straightener since SSB unbound single starnded DNA forms folds (loops) as in RNA. But it definitely is not initiator.
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REFER TYHIS WEB ADDERESS\nhttp://www.genwaybio.com
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Deoxyribonucleic acid (DNA) is a nucleic acid —usually in the form of a double helix— that contains the genetic instructions specifying the biological development of all cellular forms of life, and most viruses. DNA is a long polymer of nucleotides (a polynucleotide) and encodes the sequence of the amino acid residues in proteins using the genetic code, a triplet code of nucleotides.\nIn complex eukaryotic cells such as those from plants, animals, fungi and protists, most of the DNA is located in the cell nucleus. By contrast, in simpler cells called prokaryotes, including the eubacteria and archaea, DNA is not separated from the cytoplasm by a nuclear envelope. The cellular organelles known as chloroplasts and mitochondria also carry DNA.\nDNA is often referred to as the molecule of heredity as it is responsible for the genetic propagation of most inherited traits. In humans, these traits can range from hair colour to disease susceptibility. During cell division, DNA is replicated and can be transmitted to offspring during reproduction. Lineage studies can be done based on the facts that the mitochondrial DNA only comes from the mother, and the male Y chromosome only comes from the father.\nEvery person's DNA, their genome, is inherited from both parents. The mother's mitochondrial DNA together with twenty-three chromosomes from each parent combine to form the genome of a zygote, the fertilized egg. As a result, with certain exceptions such as red blood cells, most human cells contain 23 pairs of chromosomes, together with mitochondrial DNA inherited from the mother.\n\nMolecular structure:\nAlthough sometimes called "the molecule of heredity", DNA macromolecules as people typically think of them are not single molecules. Rather, they are pairs of molecules, which entwine like vines to form a double helix (see the illustration at the right).\nEach vine-like molecule is a strand of DNA: a chemically linked chain of nucleotides, each of which consists of a sugar (deoxyribose), a phosphate and one of five kinds of nucleobases ("bases"). Because DNA strands are composed of these nucleotide subunits, they are polymers.\nThe diversity of the bases means that there are five kinds of nucleotides, which are commonly referred to by the identity of their bases. These are adenine (A), thymine (T), uracil (U), cytosine (C), and guanine (G). U is rarely found in DNA except as a result of chemical degradation of C, but in some viruses, notably PBS1 phage DNA, U completely replaces the usual T in its DNA. Similarly, RNA usually contains U in place of T, but in certain RNAs such as transfer RNA, T is always found in some positions. Thus, the only true difference between DNA and RNA is the sugar, 2-deoxyribose in DNA and ribose in RNA.\nIn a DNA double helix, two polynucleotide strands can associate through the hydrophobic effect and pi stacking. Specificity of which strands stay associated is determined by complementary pairing. Each base forms hydrogen bonds readily to only one other, A to T forming two hydrogen bonds and C to G forming three hydrogen bonds. The GC content and length of each DNA molcule dictates the strength of the association; the more complementary bases exist, the stronger and longer-lasting the association characterised by the temperate required to break the hydrogen bonding, its Tm value.\nThe cell's machinery is capable of melting or disassociating a DNA double helix, and using each DNA strand as a template for synthesizing a new strand which is nearly identical to the previous strand. Errors that occur in the synthesis are known as mutations. The process known as PCR (polymerase chain reaction) mimics this process in vitro in a nonliving system.\nBecause pairing causes the nucleotide bases to face the helical axis, the sugar and phosphate groups of the nucleotides run along the outside; the two chains they form are sometimes called the "backbones" of the helix. In fact, it
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When looking at DNA  the genetic elements are responsible for regulation of a gene. Evidence for influence of chromatin structures impacts on transient vs stable tranfections and nulcesome core structure domen effects histone folds.\n\nYou question is an excellent question. I have a reference for you that address structure and function \n\nReferences: Chromatin Structure and Fucntion, Wolffem 1998 Academic Press\n\nThe structure is very important to function
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Those portions of DNA are probably difficult to replicate properly (or perfectly I should say).  What's the difference between 5,000 repeats and 4,995?  Not much as far as the cell is concerned.
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Please follow the links\nhttp://www.genetic-testing.biz\nhttp://www.genetic.cc\nhttp://www.genome-research.org
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Look in this website:\n\nhttp://www.ba-education.demon.co.uk/for/science/dnamain.html\n\nunder the section:\nThe people responsible for the discovery of DNA\n\nand this website:\n\nhttp://nobelprize.org/educational_games/medicine/dna_double_helix/readmore.html