What is the purpose of restriction enzymes in a DNA Strand?
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Your question is a little poorly phrased. I'll dissect it and answer the two alternatives. Restriction enzymes cut DNA at palindromic sequences. Since there are only 4 bases, palindromic sequences do abound in DNA. If you are asking what is the purpose of restriction enzyme sites on a DNA strand, there is none. It's just a convention that we scientists can utilize, unless we've engineered a plasmid with restriction sites precisely where we want them (multiple cloning region). If you are asking what is the purpose of restriction enzymes outside of being a biotechnology tool, RE evolved as a bacterial defense mechanism; sort of a bacterial immune response. Bacteria are where we got the original restriction enzymes from (nowadays we can design new ones that are really specific for what we want) and they use RE to cut up the DNA of bacteriophage that are infecting them, preventing the bacteriophage from becoming lytic and killing the bacteria.
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restriction enzymes only work in proper salt and pH condtions.  The buffer is there to mimic the conditions the enzymes normall work in.
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The process of DNA replication depends on the molecular shapes of DNA and its nucleotide bases. Adenine pairs only with thymine and guanin pairs only with cytosine (purine pairs wiht pyrmimadine). DNA synthesis occurs in 3 steps.\n1. binding of enzymes to existing DNA\n2. unwinding of double helix\n3 synthesis of new matching strand for each existing strand
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The two strands are held together by weak electrostatic forces due to the hydrogen bonds between the purines and pyrimidines - A=T\nG triple bond C\nwhere A - adenosine\n           T - thymine\n           G - guanine\n           C - cytosine \nthese are the nucleotides of which A & G are purines and C & T are pyrimidines.\nThe hydrogen bonds individually are very weak but because they are in such large numbers (millions on one DNA strand), they provide stability to the DNA molecule.\nSo, in short the two strands are held together by large a number of hydrogen bonds.
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In DNA deoxyribose-phosphate backbone and nitrogenous bases.  The bases of DNA are adenine, cytosine, guanine and thymine.  In RNA ribose-phosphate backbone and nitrogenous bases are adenine, cytosine, guanine and uracil.  A deoxyribose-phosphate backbone is essentially a pentonse sugar (5 carbons) linked to a phosphate group in a 5' to 3' direction.  The bases are connected to the 1' end of the ribose groups. Pairing occurs by hydrogen bonding between A+T, A+U, and G+C between two strands.
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Restriction enzymes, also called restriction nucleases (EcoRI in this example) , surrounds the DNA molecule at the point it seeks(sequence GAATTC). It cuts one strand of the DNA double helix at one point and the second strand at a different, complementary point (between the G and the A base). The separated pieces have single stranded "sticky-ends," which allow the complementary pieces to combine. \n\nThe newly joined pieces are stabilized by DNA ligase.\n\nEcoRI, one of many restriction enzymes, is obtained from the bacteria Escherichia coli.
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A desired sequence is isolated by using restriction enzymes.  They are enzymes that cut DNA at specific nucleotide sequences.  PCR envolves a mixture of lots of stuff, but essentially, you are using a cell called a competent cell to preform a transformation.  The cut DNA is introduced into the cell which acts like a machine to copy that DNA over and over again.  PCR means Polymerase Chain reaction.  Polymerase is the enzyme reponsible for DNA replication.
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It is a type of inhibition that occurs when a molecule, of roughly the same shape of the substrate, enters the active site of an enzyme.  It blocks the active sight and hence prevents the substrate molecule to enter active site.\n\nThe reaction's rate is decreased as not all enzymes can metabolise the substrates, some of them being blocked by the inhibitor.
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dna is a chemical code inside every living cell that determines how the cell functions.
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Well, some biological purposes of a phosphate group:\n\nAlternating phosphate groups and deoxyribose sugars form the backbone of DNA. To each sugar is attached a nitrogenous base.\n\nPhosphate groups can be removed from ATP (adenosine triphosphate), releasing a relatively large amount of energy, forming ADP and a Pi group.\n\nPhosphate groups are very negatively charged. Sometimes, cells add a phosphate group to glucose to keep it from passing through a cell's plasma membrane.\n\nAnd there are other uses..
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If you're talking about which species a strand of DNA is a part of, these are recognized by comparing to known types for degrees of similarity.  For instance, we recognize a bit of DNA as being dgog DNA if it bears resemblance to DNA we took from a dog.\n\nOther than that, each bit of DNA is iether coding or non-coding (mostly, it's non-coding--but don't let the term "junk DNA" fool you, because it's very important for structural reasons).  In the coding regions, every three neceotides forms a "codon," and every codon relates to a single amino acid in a peptide chain sequence.  These peptide chains form proteins, which are the builiding blocks for just about every function in the cell body.  Lipids, sugars, and catalytic RNAs do so functions, but other than that, virtually everything is done by proteins.  they cause motility in cells, control transport, sort things, build nucelic acids, lipids, and sugars, create energy from food, detect light and pressure and other stimuli, link cells together, send messages--pretty much everything.  We call DNA the blueprint of the organism because it is the blue print for the proteins which do most of the work in defining and controling the organism.
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I think that you may be referring to lagging strand as opposed to leading strand?\n\nWhen DNA is replicated, the two strands separate, much like a zipper, along part of their length.  Unlike a zipper, the strands are oriented in opposite directions, called anti-parallel.\n\nThe new strand to be synthesized can only be synthesized in one direction.  This means that one strand can be built continuously.  The other strand will be built in small discontinuous segments which must then be connected.  This strand is known as the lagging strand.
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The top picture looks like it's showing the relative length of genes on sections of a chromosome.  The bands on the picture that shows all of the chromosome are not genes, but regions.  The horizontal line with the vertical lines (pictures 1 and 2) through it is comparing the gene lengths.  Picture 4 looks like the electrophoresis pattern after that region of the chromosome was cut with restriction enzymes.\n\nThe bottom link is essentially the same thing, with (from top to bottom) the chromosome as a whole, the mapping of the genes on that chromosome, the restriction sites on that stretch of DNA, and the chunks of the DNA as they were cut up by restriction enzymes.
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look up Restriction Enzymes
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Because they make up your bodys DNA\n\n\nA circular strand of DNA in bacteria that contains the hereditary information necessary for cell life.
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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.
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it's true because phosphatase prevents vectors from closing in on themselves. This doesn't inhibit cloning but ehances it and allows a greater chance for the insert getting in the plasmid and not just the vector re-closing in on itself.\n\nIf you have any other questions about plasmids, cloning in bacteria, etc. feel free to contact me. I do this in lab almost daily.