on the subject of DNA transcription, does it follow the 5' -3' direction?
952537
I’m not sure what your question is.  If you mean to ask if synthesis of the new RNA transcript goes 5’ to 3’ then yes.  Synthesis must go 5’ to 3’\n\nHowever, the RNA polymerase reads the coding strand in the 3’ to 5’ direction because nucleic acids bind in an anti-parallel orientation.
32646
Synthesis\nSynthesis of RNA is usually catalyzed by an enzyme, RNA polymerase, using DNA as a template. Initiation of synthesis begins with the binding of the enzyme to a promoter sequence in the DNA (usually found "upstream" of a gene). The DNA double helix is unwound by the helicase activity of the enzyme. The enzyme then progresses along the template strand in the 3’ -> 5’ direction, synthesizing a complementary RNA molecule with elongation occurring in the 5’ -> 3’ direction. The DNA sequence also dictates where termination of RNA synthesis will occur.
1182355
Remember this: \n\nRNA (A, U, G, C)\nDNA (T, A, C, G)\n\nDNA has sequence: T-C-A-T-C-G \nmRNA would be c) : A-G-U-A-G-C
790485
I've answered a similar question in the past\n\nhttp://answers.yahoo.com/question/index;_ylt=ApDo1VHr18AJSQm6WOxC_8Dsy6IX?qid=20061028024332AAKbYkD\n\nor copy pasting...\n\n"The more bulky the molecule the harder it is for it to move through the gel pores and thus the slower it will run.\n\nThe order in a gel would be\ncircular nicked (so there is no supercoiling)\nlinear\nsupercoiled\n\nObviously from this order supercoiled is the fastest running, though sometimes it can run at the same height as linear.\n\nThe migration of linear DNA is the one representative of the actual size."
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Let's take a programmers viewpoint.\nYou would have to code the algorithm for the development of an "arm" only once, you only have to include something that will say right or left. DNA is not read twice for extremities... :) \nThere is no direct code for an extremity - an arm will grow and develop as a consequence of a multitude of genes switching on and off. It is like a chain reaction. It is the integrated function of thousands of cells that will lead to an arm.
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That DNA of different sizes will migrate through a gel at different speeds.\n\nDNA is charged, so applying an electric current will cause the DNA to migrate down the gel, the smaller the piece, the faster it goes.  So you can separete pieces of different lengths, or estimate the size of your band by comparing to a standard ladder.
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Try this , it really helped me in my first few lectures in cell bio , such as DNA and RNA . Loads of animations and stuff ! \n\nhttp://www.johnkyrk.com/DNAtranscription.html
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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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RNA starts at promoter\n\nDNA needs primer to start
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72 from above+3Termination codon=75!
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transcription in cells makes RNA copies of DNA.
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Each half of the double-helix sort-of "unzips" during replication.  Since each of the bases is kind of like a jigsaw-puzzle piece, the two strands can then wind back up, if supplied with the appropriate free bases, to form two identical copies of the original DNA strand.\n\nNeat, huh?
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DNA has the form of a double helix. It is also anti parallel.
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The important thing is to keep the helical structure clearly visible. Don't worry about the side hydrogens or details of the molecules.\n\nKeep in mind that DNA is a double-stranded helix, and the strands don't revolve around each other identically. Which means there are two sizes of 'grooves': the small grooves are a bit over half the width of the large ones.\n\nIf you use styrofoam balls for the nucleotides and join them with drinking straws (a handy way to do this project), take care that the angle subtended by three of the balls be around 35 degrees.\n\nAbout 10 balls should complete a cycle, which means ball number 11 must be above ball number 1 in a straight line.\n\nDo a strand first, so that it looks fairly twisted yet linear. Add the other strand afterwards. A length of about 20 nucleotides per strand (= 40 in total = 40 small styrofoam balls) should be enough.\n\nGo to a crafts store and buy a bag of balls (they come in 50, 100, etc.) and a bag of 100 drinking straws. Color the balls blue for cytosine, red for thymine, green for guanine and orange for adenine. Pair orange with red and blue with green when building the second strand.\n\nHope this helps.
180495
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 :>
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no, because it is a defect on human chromosome 21, where 3 copies are made instead of 2. this has never been seen to occur in the genomes of other organisms.
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UPDATE: I've just read your comment so I'm leaving the difficult stuff below. \nFirst things first:\nProbably you know (but it's worth repeating) that the genetic information in each cell is kept as DNA. This DNA is able to copy parts of itself as RNA. RNA in turn builds proteins. Our bodies are not made only of proteins, but proteins are the ultimate regulators of what our body looks like and how it works. So, if a gene in your DNA synthesizes a specific RNA, and this in turn can make a particular protein, this protein will have to do with the way you look and function. Another person with a somewhat different "variety" of the same gene, will have a different appearance and/or function. Each gene codes for one protein, so it takes a really large amount of genes to code for all of them (and this is VERY simplified, the interactions are much more complex).\n\nNow for the second part: the fact that you have several really long DNA strands in each cell (these DNA strands are what can be visualized as chromosomes under special circumstances) does not mean that every single little gene in your DNA will generate RNA and ultimately produce a protein. Only a part of the DNA is actually active (and it's a small proportion), the rest is just "there" and doesn't code. And the expression of the gene (=when the gene's information becomes visible) depends on the interaction with other genes, with other substances that are cellular regulators, and many environmental factors. \n\nExample: you know Siamese cats? they have a genetic constitution such that the dark color proteins are formed especially at the body parts that are colder. So usually you get a sand-colored cat with black legs, tail, and ears. But for this pattern to show, there has to be interaction with the right temperatures. If the cat is not exposed to these colder temperatures, the dark parts don't develop. Or maybe other proteins or regulators "got in the way" of the process. And you get a cat with no dark parts (or the opposite, a very dark animal from excess cold). \nAnother example: suppose a baby is born from tall parents; they in turn had tall parents, so it's highly probable that the baby has the "tall" potential. But if this baby is not well nourished during his/her development, he/she will not reach the height that he "potentially should" have had. \nCan you see the difference? The genotype is ALL the genetic information that you have, and the phenotype is the result of the combination of this genetic information with other factors: the person/animal/plant as it is realized. \nI hope this helps you, I'll be around :-)\n\nCheck this site, it's great:\nhttp://evolution.berkeley.edu/evosite/evo101/IIIA1Genotypevsphenotype.shtml\n-------------------------------\nThe genotype is the genetic information that the said individual carries in each of his/her body cells. Much of that information is never expressed (=becomes "visible" or translates into actual characteristics), and much genetic information can yield different characteristics depending on the interaction with many environmental factors (which occur both inside and outside the cell or organism in question). Thus, the final fully developed individual is the result of the genotype ("raw" genetic information) PLUS environmental/developmental factors; the characteristics of this final product, the real individual, constitute the Phenotype. \nFor instance, an individual with a perfectly "normal" genotype may develop many types of abnormalities due to problems during pregnancy, including drugs, lack of oxygen, etc. Identical twins have the same genotype (they come from a single cell) but are never completely identical; and of course they have different personalities. This is because of all the epigenetic phenomena that influence development. And it's also the reason why reductionist approaches that s