This unit helps you understand the properties of nucleotides and how they contribute to secondary and tertiary structures of nucleic acids at the molecular level. You will learn about the different composition and roles of nucleic acids in the cell, their interactions with each other and the use of ribozymes, aptamers, antisense and hybridization as tools in molecular research. The unit covers the function of DNA packaging within the cell, the interactions between the DNA double helix and the nucleosome and it helps you understand the various chromatin states within the interphase nucleus. This study unit is just one of many that can be found on LearningSpace, part of OpenLearn, a collection of open educational resources from The Open University. Published in ePub 2.0.1 format, some feature such as audio, video and linked PDF are not supported by all ePub readers.