how are adenine and guanine different from thymine and cytosine?
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Adenine and guanine are what we call purines whereas thymine and cytosine (and you could add uracile) are pyrimidines. The main difference is the molecular structure of these nucleobases. Purines are made of two cycles and Pyrimidine are each made of one cycle. In the DNA and RNA molecules pyrimides pair with purines.
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a mutation can change the DNA but not the amino acid sequence because in order to get a protein there are several options for DNA. (for example) you can UAG as a protein and you can get that by ATG, CGC, AUC and more.  So that gives you a chance to get the same amino acid with a change in the DNA.
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There are both structural and functional differences between DNA and RNA. \nThe structure of the nucleotids that form each molecule is different (DNA has desoxyribose and RNA has 'normal' ribose); and while DNA is formed by the combination of the nucleotids Adenine, Timine, Citosine and Guanine, RNA has Adenine, Citosine, Guanine, but Uracil instead of Timine.\n\nThey also differ in their 3-D structure: DNA is a double strand forming a helix, and RNA is single stranded, with different shapes according to the types of RNA. \n\nThat's another difference: there are 3 distinct types of RNA (transfer RNA or RNAt, ribosomic RNA or RNAr, and messenger RNA or RNAm). These three types have different functions and are found in different parts of the cell; they're smaller molecules that can go outside the cell nucleus, whereas the large DNA molecule stays within the nucleus and has a single function: provide and perpetuate the genetic information of the individual.
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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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A DNA nucleotide ia made up of:\n1- phosphate \n2- deoxyribose sugar\n3- one of the 4 nitrogeneous bases: adenine, thymine, cytosine or guanine.
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DNA is double stranded with Deoxyribose, and has the nucleic acids Guanine, Cytosine, Thyamine, and Adenine (GCTA)\n\nRNA is single stranded with ribose, and has the nucleic acids Guanine, Uracil, Adenine, and Cytosine (GCUA)\n\nUracil replaces Thyamine
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They are:\n\n1) Gene\n2) Nucleotides\n3) Nitrogen Bases - Guanine, Cytosine, Adenine and Thymine\n5) Phosphodiester bond\n6) Sugar\n7) Phosphate group\n\n\nArranged are the substances, from big to small\n\nA DNA is composed of segments of genes\n\nThese genes are known as nucleotides\n\nIt takes 2 chains of nucleotides to form a DNA\n\nA chain of nucleotides are formed by sugar phosphate backbone (one strand)  - phosphodiester bond\n\nOne nucleotide is made up of a nitrogen base (either Adenine, Thymine, Guanine or Cytosine), a sugar (deoxyribose) and a phosphate group.  \n\n\n\nNow, how do 2 strands of nucleotides bond together?\n\nThere are hydrogen bonds existing between the nitrogen bases and 3 hydrogen atoms completes the bond between Guanine (G)and Cytosine (C).  2 hydrogen atoms competes the bond between Adenine (A) and Thymine (T).  It is a rule that G always binds with C and A with T. \n\nillustrated below is a portion of DNA\n\n--------------------- <-- phosphodiester bond\n C C G G A T T   <-- nitrogen bases\n ```````````````````\n HHHHHHHHH   <-- hydrogen atoms\n ```````````````````\n G G C C T A A   <-- nitrogen bases\n---------------------  <-- phosphodiester bond
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Purine Bases form hydrogen bonds with Pyrimidine Bases\n\nPurines are Adenine , Guanine\nPyrimidines are Cytosine , Thymine (and Uracil in RNA)\n\nAdenine only forms a double hydrogen bond with Thymine (or Uracil)\nGuanine only forms a triple hydrogen bond with Cytosine
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Are you talking about Adenine, Thiamine, Cytosine, and Guanine?\nAmino Acids.
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Consider a regular climbing ladder.  If the ladder was sawed in half by sawing each rung crosscut thru the middle than each half of the ladder would represent one  DNA strand.  Each new organism receives a single strand from each of it's parents.  The two strands join to make the new organism's double stranded DNA.  The rail or sides of the ladder would represent the sugar and phosphate link backbone of the DNA.  The sawed rung would represent the nucleic acid bases.  The bases are classified as either purines or pyrimidines.  The two purines are Adenine (A) and Guanine (G) which are similiar to the compound Purine.  The two pyrimidine bases are Thymine (T) and Cytosine (C) which are structured similiar to the compound Pyrimidine.  In RNA Thymidine is replaced by Uracil.  The collective term for these structures is "nitrogenous base".  Each base contains either/or hydrogen (h), nitrogen (n) and oxygen (o) atoms located on the structure where the "cut" would exhist on the sawed ladder rungs.  When these bases move close together there is an attraction between these atoms and a bridge forms called a hydrogen bond  or h-bond.Thymine has an o and a h.  Adenine has a h which is attracted to T's o and an n which is attracted to T' h. A and T always h-bond or pair.  Cytosine has an h,n,and o.  Guanine has two h's and an o.  one h on guanine is attracted to the o on cytosine, the other to the n.  The o is attracted to the h on cytosine.  Therefore C always pairs with G and is held together by three h-bonds, where A and T are paired by two h-bonds.  In total the h-bonds strongly bind the two DNA single strands together but one at a time they can be broken to seperate the strands much like a zipper opening link by link.  Since C always pairs with G their proportion is is always the same.  The same is true for A and T.  Each Dna single strand has what is called a 3' (three prime hydroxyl) and a 5' (five prime phosphate) end.  When the two single strands pair to form thd Double strand they Form with the 3' end of one strand joining at the 5' end of the other strand.  This is known as antiparallel since they are running in opposite directions.
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GGATCGA\n\nGuanine pairs with adonine and cytosine pairs with thymine.
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-Both DNA and RNA are nucleic acids.\n- Their building blocks are nucleotides.\n- They both have phosphate.\n- They both have a 5-C sugar eventhough the sugar is different(deoxyribose in DNA and ribose in RNA)\n- They both have 4 nitrpgeneous bases.\n- 3 of the bases are common to both: adenine, cytosine and guanine.
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All bases are present in DNA except URACIL and in RNA it is THYMINE. Adenine is joined with Thymine in DNA, as well as Cytosine is with Guanine. In RNA, The only difference is that Adenine Joins with Uracil. Guanine and Cytosine still Join together.
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DNA is the building blocks of life (I know you've heard that one). Basically, DNA encodes everything. It's what creates cells.\n\nIn a nutshell, DNA is comprised of a basic 5-carbon sugar with an attached nucleic acid (one of four, adanine, guinine, cytosine, and thiamine). These form long chaings that if stretched out fully would encompass the earth around 5 times. They encode (in a lengthy process) for protiens and certain protein chains that in the end, make your cells. And more cells, and more, until you get an organ. Enough organs and you get an organism. \n\n-Eric
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'coz most of the microorganisms have MORE cytosine-guanine bond IN THEIR DNA OR RNA which is bounded by three hydrogen bonds as compared to adenine-thymine or adenine-uracil bonds,hence more temp. and energy is required to break the triple hydrogen bonds,hence they can tolerate EXTREMITIES OF TEMP.
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B) RNA is found only inside the nucleus, whereas DNA is found only outside the nucleus.\n\nIn order for the statement to be true, the subjects (RNA & DNA) should be switched.
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its a double helix.\n\n  \n 1. DNA is made up of subunits which scientists called nucleotides.\n   2. Each nucleotide is made up of a sugar, a phosphate and a base.\n   3. There are 4 different bases in a DNA molecule:\n\n          adenine (a purine) \n          cytosine (a pyrimidine) \n          guanine (a purine) \n          thymine (a pyrimidine) \n\n   4. The number of purine bases equals the number of pyrimidine bases\n   5. The number of adenine bases equals the number of thymine bases\n   6. The number of guanine bases equals the number of cytosine bases\n   7. The basic structure of the DNA molecule is helical, with the bases being stacked on top of each other