Nuclein is the material found in the nucleus, consisting mainly of nucleic acids, protein, and phosphoric acid. In 1869, Friedrick Miescher discovered nuclein in eukaryotic cells.Ian Cuming / Getty ImagesĬonsiderable research in the 19th and 20th centuries led to the understanding of the nature and composition of the nucleic acids. A pyrimidine bases consists of a single ring or heterocyclic amine.ĭNA may be the largest natural molecule. Cytosine and thymine are called the pyrimidine bases. They are bicyclic molecules, which means they consist of two rings. You can remember that U corresponds to T if you recall U follow T when you recite the alphabet.Īdenine, guanine, and thymine are called the purine bases. A and T are both letters made of intersecting straight lines. C and G are both curved letters of the alphabet. One easy way to remember which bases pair with each other is to look at the shape of the letters. Base pairs form the same way, except adenine joins to uracil (A-U), with guanine bonding with cytosine (G-C). RNA is made using the bases adenine, uracil, guanine, and cytosine. Adenine and thymine bond (A-T), while cytosine and guanine bond (G-C). The bases bond to each other in a very specific way. The link between the nucleotides is called a phosphodiester bond.īoth DNA and RNA are made using bases, a pentose sugar, and phosphate groups, but the nitrogenous bases and the sugar are not the same in the two macromolecules.ĭNA is made using the bases adenine, thymine, guanine, and cytosine. When nucleotides bond to each other to form DNA or RNA, the phosphate of one of the nucleotides attaches to the 3-carbon of the sugar of the other nucleotide, forming what is called the sugar-phosphate backbone of the nucleic acid. The number 5 carbon of the sugar bonds to the phosphate group. The primary or first carbon of the sugar links to the base.
The bases and the sugar are different for DNA and RNA, but all nucleotides link together using the same mechanism. ALFRED PASIEKA/SCIENCE PHOTO LIBRARY / Getty Imagesīoth DNA and RNA are polymers made up of monomers called nucleotides. DNA contains sections called genes, which encode the body's genetic information. There are four different bases: guanine, cytosine, thymine and adenine. DNA is composed of two sugar-phosphate backbones and nucleotide bases.
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