Year: 2013
Type: dissertation
Abstract: In nature, the hereditary material that contains the instructions for making all living matter is\nknown as deoxyribonucleic acid (DNA). Almost all the cells in our body, except mature red\nblood cells, have DNA of which the vast majority is located in the nucleus. DNA is composed of\nlong stretches of nucleotides, which themselves are build up of sugar (deoxyribose), phosphate,\nand two kinds of nucleobases, i.e. purines and pyrimidines. The purine bases comprise adenine\n(A) and guanine (G), whereas the pyrimidines consist of cytosine (C) and thymine (T). In general,\nDNA is formed by two nucleotide strands which together assemble into a double helix structure\n(Watson and Crick, 1953). Within this double-stranded helix, the nucleobases present in opposite\nstrands form hydrogen bonds with each other in such a way that adenine forms base pairs with\nthymine (A-T) and cytosine pairs up with guanine (C-G). As a consequence of this base pairing,\nthe nucleobases adenine and thymine and cytosine and guanine are present in approximately\nequal amounts, with A and T each accounting for roughly 30%, whereas C and G each make up\n20% of the four bases in human (Chargaff et al., 1950). The relative amounts of A, G, C, and T\nand, therefore, the composition of DNA vary from one species to another though.\nThe DNA can be divided into several functional domains, such as genic and non-genic\nregions. The genic regions contain genes, which are pieces of DNA encoding either protein or\nnon-coding ribonucleic acid (ncRNA). In case of the protein-coding genes, information\nembedded within these genes is transmitted by an intermediate molecule, the messenger RNA\n(mRNA). This occurs through a process called transcription, which will be explained in more\ndetail later on. The non-genic regions often fulfill regulatory functions which are important for\ngene transcription.
Author: Olaf Voets
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W1561102604