What are the four bases of RNA

RNA and DNA

RNA and DNA

Ribonucleic acids (RNS, more often English: ribonucleic acid, RNA) are organic acids that play a key role in the formation of new proteins in cells (protein biosynthesis). They are in the form of single-stranded, thread-like macromolecules in the nucleus and cytoplasm of the cells. Human RNA is composed of four organic bases: adenine, guanine, cytosine and uracil, which are linked by a sugar and phosphate backbone. The combination of one sugar, one phosphate residue and one of the four bases is called a nucleotide. The nucleotides form the basic building blocks of RNA and DNA.

There are different types of RNA that serve different functions. The mRNA (messenger RNA) is used, for example, to transmit information from the cell nucleus to the ribosomes, with the help of which proteins are synthesized. The tRNA (transfer RNA) serves as an auxiliary molecule in the provision of individual amino acids for protein biosynthesis from the cytoplasm to the ribosome, and a good two thirds of the ribosomes themselves also consist of ribonucleic acid, the rRNA (eng. : ribosomal RNA, Ger .: ribosomal RNA). Certain ribonucleic acids can also have gene-regulating functions or transmit genetic information.

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The deoxyribonucleic acid (DNS, more often English: deoxyribonucleic acid, DNA) is like the RNA a nucleic acid, which however stores the genetic information of a cell and thus represents the substance from which the genes are made. The structure of RNA and DNA is similar. The DNA molecule also consists of a backbone of sugar and phosphate and four different bases. Of these, three - adenine, guanine and cytosine - are identical to those in RNA. Instead of uracil, however, thymine is added as a fourth base. The sugar that links the bases together with the phosphate is also slightly different. Unlike RNA, it is not ribose, but deoxyribose - hence the different names of the two acids.

In contrast to single-stranded RNA, DNA is double-stranded. The structure of DNA, which was discovered in 1953 by scientists James Watson and Francis Crick, corresponds to a double helix. This can be imagined as a spiral-shaped twisted rope ladder, with the longitudinal connections always alternating between a sugar and a phosphoric acid and the cross connections each consisting of two of the four bases, which are connected to each other by transient hydrogen bridge connections. The sequence of three bases or nucleotides each represents the genetic code (codon) for an amino acid.

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variants

  • Nucleic acids (RNA or DNA)