DNA is the single most important molecule found within cells. It is a stable polynucleotide, which contains coded information for inherited characteristics. It is contained in chromosomes in the nucleus of an eukaryot cell. The essential features of the Watson-Crick model are summarised below. 1. The two helical polynucleotide chains are coiled around a common axis. The two chains have opposite polarity i.e. they are antiparrallel. 2. The regular repeating sugar phosphate backbone of each strand …
showed first 75 words of 427 total

showed last 75 words of 427 total
…and the nucleic acids that they make up, their acidic character. The phosphate group is chemically reactive and allows new groups to be added by condensation reactions. More complex strands can be built up, and the nucleotides can be linked together to form a polynucleotide chain. These three components when joined form a nucleotide: The three parts of a nucleotide monomer are joined by condensation reactions. Two molecules of water are removed in the process.