Pyrimidine

Under oxidative conditions, certain nucleobases (for example, adenine and cytosine) can form N-oxides. Also, the C8 position of guanosine is vulnerable to hydrolytic attack under either strongly acidic or strongly alkaline conditions. The 5,6 double bond of pyrimidine nucleosides also reacts with halogens and halohydrins to give the corresponding addition products (Shabarova and Bogdanov, 1994). Selected examples of the side reactions that occur during oligonucleotide synthesis are given below. Tri-O-acetyluridine (S.1) reacts with MSNT to produce the triazolo derivative S.2 (Figure 2.1.2; Reese and Ubasawa, 1980). During deprotection with ammonium hydroxide, S.2 gives cytidine (S.3). Interestingly, during deprotection with either the tetramethylguanidinium…

1. Pyrimidines are heterocyclic aromatic amines which, together with purines, form nucleotides. Nucleotides are the building blocks of nucleic acids, the basic structural component of DNA and RNA. The pyrimidines in DNA are cytosine and thymine, and in RNA uracil replaces thymine (Bettelheim, Brown, Campbell, Farrell & Torres, 2013). 
DNA and RNA are found in the nuclei of all cells and their job is to transmit the information needed for cellular growth and reproduction (Averill & Eldredge,…

The nucleotides are linked by phosphodiester bonds that connect the 5’ carbon of a nucleotide to the oxygen on the 3’ carbon of neighboring nucleotide. The Oxygen and Nitrogen atoms of nucleotide create a polarity on the backbone of nucleotide sequences. An important distinction between DNA and RNA is the nucleotide composition. DNA and RNA both contain purines, Adenine (A) and Guanine (G). However, DNA contains pyrimidines, Cytosine (C) and Thymine (T), whereas RNA only contains pyrimidines…

Heterocyclic Bases There are five different bases are found in nucleotides of DNA and RNA. Only 4 bases are present in DNA and 4 bases are present in RNA. They are all heterocyclic bases. They are nitrogenous bases as they contain nitrogen in their rings. They form nitrogenous bonds with each other. Some bases are one ring bases and are similar in structure to the compound pyrimidine. Because of that, they are given names as the pyrimidines or the pyrimidine bases. There are three of them and…

Each nucleotide is made up of one phosphate group (PO4), a five-carbon sugars (pentose),one of five nitrogenous base molecules, and one or more phosphate groups. The nitrogenous base contains one or more rings that have nitrogen atoms. To assemble the nucleotide, a phosphate group is attached to the five-carbon. Nucleotides are then linked in a dehydration reaction. Adjacent nucleotides are then joined in a phosphodiester linkage. A phosphate group links the sugar of the nucleotide. B. 1. The…

The bases all happen to be heteroaromatic, as they contain two different elements in their aromatic system, namely carbon and nitrogen. The purines, containing two rings, are an example of a fused ring system, where in fact the electrons in what appear to be two distinct rings are delocalised across the whole ring system as one. The pyrimidines, which contain only one ring, also have delocalised electrons, as all aromatic molecules do. The double stranded DNA molecule is formed when these…

Adenine and Guanine are Purines as they have a double ring structure whereas Cytosine and Thymine are Pyrimidines as they have a single ring structure. These bases, attached to the sugar-phosphate back bone of both strands, join adjacently in a complimentary fashion. This means that a purine will bind to a pyrimidine therefore Adenine always binds with Thymine, which forms two hydrogen bonds, and Guanine always binds with Cytosine, which forms three hydrogen bonds. This is known as complimentary…

on the control and experimental plates, prove that UV light does not target particular spores for mutations, according to the University of California Museum of Paleontology mutations occur randomly, however they can be affected by the environment, as seen in this experiment. In this experiment exposing the Penicillium notatum to UV the likelihood of mutations increased, but some or most mutations could have been a result of random inherited mutations. The experimental plate exposed to UV…

think how this vast set of molecules that are in every living thing, from bacteria to human beings, are mostly made up by six elements (carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus). These biopolymers have the properties to, from small monomers, build giant tridimensional structures with a lot of different functions. How physical and chemical properties of atoms make these macromolecules possible? What is the chemistry behind their three dimensional configuration? Chemistry inside…

Daniel Huang Chapter 9 1. Mutations can be very negative in that it can cause cancer in somatic cells. However it is important to note that mutations will also lead to variability which is beneficial to us. Mutations in intergenic DNA affects regulations of protein products which is actually less detrimental than mutations in exons which code for the proteins. 2. Transition is the error that causes the base to change from a purine to purine or pyrimidine to pyrimidine. Transverses are base…