In this article we will discuss about the molecular structure of nucleic acids, explained with the help of suitable diagrams. Nucleic acids are macromolecules present in all living cells, either in free state, or in combination with proteins to form nucleoproteins. Besides, the simplest viruses consist exclusively of a molecule of nucleic acid enclosed in a protein shell. We will [...]
In this article we will discuss about the process of biosynthesis of RNAs. The polymerization of ribonucleosides-5'-triphosphates to RNA is a process called transcription, because the genetic information carried by the DNA is transcribed into RNA. This transfer of information is based on the same principle as the duplication of DNA, i.e. the pairing of complementary bases (we will see [...]
The replication of the DNA can be schematically divided in three steps: initiation, elongation and termination. Step # 1. The Initiation Step: As seen above, no DNA polymerase can perform any de novo synthesis (contrary to RNA polymerases which can initiate by placing a complementary ribonucleoside-5'-triphosphate opposite to the DNA to be transcribed). The primer 3'OH which will serve as [...]