what does the bas sequence in a DNA molecule do?
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The base sequences in DNA are arranged in particular order along the sugar- phosphate backbone. The sequence specifies the exact genetic instructions required to create a particular organism with its own unique traits. \n\nThere are specific sequence of nucleotide bases, whose sequences carry the information required for constructing proteins, which provide the structural components of cells and tissues as well as enzymes for essential biochemical reactions.
874345
DNA is composed of 4 bases: adenine (A), thymine (T), cytosine (C), and guanine (G). Uracil (U), is rarely found in DNA except as a result of chemical degradation of Cytosine, but the DNA of some viruses (notably PBS1 phage DNA) and RNA (Ribonucleic Acid), has Uracil instead of Thymine.\n\nEach base on one strand forms a bond with just one kind of base on another strand, called a "complementary" base: A bonds with T, and C bonds with G. Therefore, the whole double-strand sequence can be described by the sequence on one of the strands, chosen by convention. Two nucleotides paired together are called a base pair.\n\nIn a DNA double helix, two polynucleotide strands can associate through the hydrophobic effect and pi stacking. Which strands associate depends on complementary pairing. Each base forms hydrogen bonds readily to only one other base, 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 temperature required to break the hydrogen bond, its melting temperature (also called Tm value))-.
177423
It binds to a specific sequence of the gene. If the gene is present, it will bind, if not, it will not bind. Usually the probe also has a fluorescence end, therefore you can use a light to show that it did bind or not.
627185
the gel is like a matrix which offers reistance to the fragments of dna.  the dna has polarity which means it will be effected by electric current.  when the electricity passes through the gel and the wells with the sample, it picks up bits of the dna and carries it toward the other end of the gel.  smaller pieces hit less resistance from the gel and travel quicky.  larger pieces hit more resitance and travel slowly.  \n\nusually there will be a control or a ladder that will travel along at the same time.  you can compare the distance your dna fragments travel to the ladder and you'll know aproximately how many base pairs are in each band.
230683
I respectfully disagree with the previous answer.\n\nGranted, X-Ray crystallography was used to discover the structure of DNA, but it was not used to sequence DNA.  Educated guesswork would not come close to sequence some billions of base pairs.  What is used is a "shotgun" approach, developed by Craig Venter (I hope I spelled that right) of Celera Genomics.  Essentially, it sequences random fragments of DNA, and a computer puts these fragments together into a sequence.  \n\n1. Between two random humans, ~99.9% of their DNA sequence will align.  Aside from the fact that sequencing one person's DNA would be impractical, one person probably wouldn't represent a "human" genome particularly well.  A group of volunteers was actually used in the Human Genome Project.  In other words, the current sequence used today is not from one person, but from many people.\n\n2. The genome was sequenced not as a random series of G's, A's, C's, and T's (I guess in a way it was), but it was sequenced with the intent to study various functional units --genes.  Funnily enough, most people's genes are pretty much the same.  Even more odd is the fact that a human gene that codes for a particular protein is typically nearly identical to homologous genes in other species.  Some proteins that we have even have homologies with bacteria and plants!  (Conclusion: DNA sequences between humans, and even between species, like chimps, are really really similar)\n\n3. This is not to say that everyone's DNA are exactly identical, but they are close enough where groups of volunteers could be used.     \n\n4. Just in case you're curious, even though our DNA and a chimp's DNA are almost identical, I don't know about you, but I'm not a chimp.  The reason for this (and the focus of much biology research today) is how our genes are regulated versus how a chimp's genes are regulated.  \n\nSorry for the long answer, but I really like this stuff.  It's what I do.
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A single nucleotide change in a DNA sequence can result in a change in the codon that could then lead to a change in the amino acid that is made in the protein.  When proteins have a mutation in their amino acid sequence due to the change in DNA sequence, you can get a protein that no longer functions.  This often leads to a disease, and that is a profound effect on a phenotype.  If a DNA change occurs in the promoter of a gene, it's possible that gene which is normally transcribed won't be any more because the transcription factor does not bind recognize the new sequence.  You can also get frame shifts, which would result in a nonsense amino acid sequence.
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http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20101/Bio%20101%20Lectures/DNA/dna.htm
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Restriction Enzymes: \n\n \n\nThese are enzymes that cleave the strands of DNA at specific sites, according to the nucleotide sequence. They are counterparts of proteolytic enzymes such as trypsin, chymotrypsin in the world of nucleic acids. They are highly specific, and the sites they recognize may be very rare. Restriction enzymes are found in nature, primarily produced by bacteria as part of a defense system. \n\nThere are several types of restriction enzymes. We will focus on Type II, which is the type most widely used experimentally. \n\nNuclease: an enzyme that cleaves a nucleic acid\n\nRestriction Endonuclease: an enzyme that cleaves within a segment of nucleic acid, when it recognizes a specific sequences of bases. (Restriction enzyme)\n\nTypically, they are dimeric, and cleave at symmetrical sequences of DNA.\n\nExamples EcoR I and BamH I\n\n(See Chime link)\n\nHow do Restriction Enzymes recognize particular sequences of DNA?\n\nDo they open up the strands, in order to see the bases?\n\nNo, they bind along the major or minor grooves, and interact with the edges of the bases, for sequences specificity, \n\nand also with the sugars and the phosphates, for non-specific binding. This involves, H-bonding, hydrophobic contacts, and electrostatic interactions (ion pairs).
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DNA is composed predominantly of a phospho-ribose sugar backbone.  Due to the high phosphate content (which is negatively charged), the DNA molecule has an overall negative charged and migrates towards the positive electrode in a gel system (such as agarose or polyacrylamide).  \n\nThe positive electrode is referred to as the "anode" and is commonly the Red electrode in these systems - DNA "runs to Red".
110372
Cytosine and guanine are nitrogenous bases in DNA that are part of the nucleotides. These parts are used to code for genes in transcribing and translating DNA into proteins. Cytosine and guanine are always across from eachother on each side of the DNA double helix and connect with eachother by hydrogen bonds.
836450
The reason repetitive sequences often do not affect the carrier's phenotype is because many repetitive sequences are in what we know as "introns" or unexpressed regions of DNA. While our DNA contains an enormous amount of data, often only a small sequence of nucleotides is necessary to make the proteins that produce a phenotype. These active sequences are in expressed portions of the DNA, or "exons." In addition, sometimes a single strand of DNA carries sequences for many different types of characteristics in an individual, but have different portions of the DNA expressed. Therefore, what may be an intron for, say, eye color, may be an exon for hair color.
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dna and genetic coding of chromosomes.
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The enzyme is built to attach itself to a particular sequence of nitorgenous bases.  Because the A, T, G, and C (if you know what restirction enzymes are, I'm assuming you'll know the abbreviations) are structured slightly differently, the enzyme won't properly fit on any of the other sequences, and without a proper fit, it would cut your DNA strand.
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Ok, the ones of the left side are first base in codons, the ones on the very top are second base in codons, and the ones on the very right are third base codons. So you read it in 1,2,3 order. Lets say your reading a codon like... AAT, so you would look at the A on the left look under THE A column at he top, then drag your finger from the first T on the right, and the amino acid would be leucine. I'm taking Bology too except CP. Hope I helped!!!
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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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umm, ok, i don't know what the heck the first answerer is talking about (no offense answerer). anyway, what i just learned in biology today, is that DNA is the genetic code for life. it's shape is called a double helix and it looks something like what's shown below. the two sides are made up of alternating sugar and phosphate units. To be specifc, the sugar is deoxyribose.  And then the "bars" in between are nucleotides, which are the building blocks of nucleic acids(DNA stands for Deoxyribonucleic acid). There are four types- adenine, cytosine, thymine, and guanine. the "bars" are made of two of these nucleotides paired together. adenine always pairs with thymine, and guanine always pairs with cytosine. so yeah, i hope that that helps you out. im actually just learning about all of this right now in 10th grade biology.\n\n|_____|\n|_____|\n|_____|\n|_____|\n|_____|
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hiya, if you mean how does it happen here goes:\nDNA from the nucleus is transcribed to form messenger RNA (mRNA) which then carries the information from the DNA out of the nucleus to the ribosomes which are attached to the endoplasmic reticulum its here that the proteins are synthesised. Not all of the DNA actually codes for proteins and the code that is carried on the mRNA contains special sequences that control the start and stop of the protein synthesis these are called start and stop codons, a codon just being a set of 3 bases which code for something, in the case of proteins a specific amino acid. The ribsome will then read the series of codons that is between the start codon (AUG) and the stop codon (UAG, UUA etc) each codon has a corresponding tranfer RNA (tRNA) which brings in a specific amino acid. As the tRNA interacts with the mRNA the amino acids join with peptide bonds to form the long chain protein, this continues until the entire frame of the mRNA sequence is read and the protein is fully synthesised.\nHope this more or less answers your question :>