Main subjects:
3.1. Nucleic acid structure
3.2. DNA biosynthesis (replication)
3.3. Repair of damage and correction of errors
3.4. RNA biosynthesis (transcription). Posttranscrip-tional RNA modifications
3.5. Protein biosynthesis (translation)
3.6. Inhibitors of template biosynthesis
3.7. Regulation of protein biosynthesis in eukaryotes
3.8. Mechanisms of genetic mutation. Protein polymorphism. Hereditary diseases
3.9. Application of DNA technologies in medicine
Nucleic acids and proteins are informational molecules. DNA is a repository of genetic information. In eukaryotes DNA is found mainly in the nucleus and partly in mitochondria. In the genome - the complete set of all DNA molecules in the cell - the structure of all proteins and RNA molecules of given organism is encoded. In the process of DNA synthesis (replication) new DNA molecules are formed on the template of parental DNA. During division the daughter cells receive full set of genes which are identical to maternal cell. DNA repair corrects the alterations in genetic material occurring in the course of recombination (exchange of genetic material between chromosomes) and damages in DNA structure. Although the mechanisms of repair remove the majority of lesions in DNA,
but some of them remain and can cause mutations leading to inherited or oncologic diseases.
According to the central biological dogma the genetic information flows from DNA through RNA to protein. The realization of this information in the cell includes two processes: transcription (RNA synthesis) and translation (protein synthesis). During transcription messenger, transfer and ribosomal RNAs are synthesized in the nucleus on the template of DNA. From the nucleus these molecules enter cytoplasm and take part in the protein synthesis. Thereby in the process of translation the information of protein structure encoded in DNA and copied to mRNA is realized to amino acid sequence of proteins. The matrix nature of nucleic acids and proteins synthesis provides the high degree of information reproduction accuracy.