Central Dogma- Replication, Transcription, Translation


The central dogma of molecular biology is a concept that explains how genetic information is stored and expressed in living cells. It was first proposed by Francis Crick in 1958 and later refined by him in 1970. The central dogma states that the sequence of nucleotides in DNA determines the sequence of nucleotides in RNA, which in turn determines the sequence of amino acids in proteins. In other words, DNA makes RNA, and RNA makes protein.

DNA, RNA and protein are the three major types of biopolymers that carry information in biological systems. DNA (deoxyribonucleic acid) is a double-stranded molecule that stores the genetic code for all living organisms. RNA (ribonucleic acid) is a single-stranded molecule that transfers the genetic code from DNA to the protein-making machinery of the cell. Protein is a chain of amino acids that performs various functions in the cell, such as catalyzing reactions, transporting molecules, signaling pathways, and providing structure.

The central dogma describes how the information flows from one biopolymer to another in a specific direction. However, it does not imply that all information transfer is one-way or irreversible. There are exceptions and variations to the central dogma that allow for reverse or alternative information transfer under certain conditions. These exceptions and variations will be discussed later in this article.

The central dogma is important for understanding how life works at the molecular level. It reveals how the genetic information encoded in DNA is translated into functional proteins that carry out various cellular processes. It also provides a framework for studying how mutations, gene expression, and gene regulation affect the phenotype and evolution of organisms. The central dogma is one of the most fundamental and influential concepts in modern biology.