RNA is more resistant to damage from UV light than DNA. RNA’s larger helical grooves mean it is more easily subject to attack by enzymes.ĭNA is vulnerable to damage by ultraviolet light. RNA, containing a ribose sugar, is more reactive than DNA and is not stable in alkaline conditions. RNA forms in the nucleolus, and then moves to specialised regions of the cytoplasm depending on the type of RNA formed.ĭue to its deoxyribose sugar, which contains one less oxygen-containing hydroxyl group, DNA is a more stable molecule than RNA, which is useful for a molecule which has the task of keeping genetic information safe. RNA shares Adenine (‘A’), Guanine (‘G’) and Cytosine (‘C’) with DNA, but contains Uracil (‘U’) rather than Thymine.Īdenine and Thymine pair (A-T) Cytosine and Guanine pair (C-G)Īdenine and Uracil pair (A-U) Cytosine and Guanine pair (C-G)ĭNA is found in the nucleus, with a small amount of DNA also present in mitochondria. The bases in DNA are Adenine (‘A’), Thymine (‘T’), Guanine (‘G’) and Cytosine (‘C’). RNA contains ribose sugar molecules, without the hydroxyl modifications of deoxyribose. The sugar in DNA is deoxyribose, which contains one less hydroxyl group than RNA’s ribose. A large RNA molecule might only be a few thousand base pairs long. RNA molecules are variable in length, but much shorter than long DNA polymers. A chromosome, for example, is a single, long DNA molecule, which would be several centimetres in length when unravelled. RNA sometimes forms a secondary double helix structure, but only intermittently.ĭNA is a much longer polymer than RNA. RNA strands are shorter than DNA strands. RNA only has one strand, but like DNA, is made up of nucleotides. Each nucleotide contains a phosphate, a 5-carbon sugar molecule and a nitrogenous base. These strands are made up of subunits called nucleotides. RNA converts the genetic information contained within DNA to a format used to build proteins, and then moves it to ribosomal protein factories.ĭNA consists of two strands, arranged in a double helix. It is a blueprint for all genetic information contained within an organism. RNA – A comparison chartĭNA replicates and stores genetic information. These include the two molecules’ functions, their structure, their average length, the sugar (DNA contains deoxyribose and RNA contains ribose) and base molecules (RNA contains uracil rather than thymine) they contain, their location and their reactivity to enzymes and ultraviolet light. A carbanion is a nucleophile (from “nucleus” and phile), an electron-rich species that has a pair of electrons available to share with another atom.There are several differences that separate DNA from RNA. The methyl anion (CH 3 −) has a structure that is similar to NH 3 with its lone pair of electrons, but it has a much stronger tendency to share its lone pair with another atom or molecule. Because it has a strong tendency to share its lone pair with another atom or molecule, a carbanion is a nucleophile.Īdding an electron to a radical produces a carbanion, which contains a negatively charged carbon with eight valence electrons (part (c) in Figure 24.3.1). (c) The simplest organic carbanion is CH 3 −, which has a trigonal pyramidal structure with an sp 3 hybridized carbon that has a lone pair of electrons. It is also sp 2 hybridized, but there is a single electron in the unhybridized p orbital. (b) The methyl radical (♼H 3) is a radical that, like the carbocation, is trigonal planar and an electrophile. Its structure is trigonal planar, with an sp 2 hybridized carbon and a vacant p orbital. (a) The simplest carbocation is the methyl cation (CH 3 ), which has six valence electrons and is an electrophile. \): Transient Intermediates in Organic Reactions.
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