RNA WORLD Meaning and
Definition
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The RNA world is a hypothetical era in the early evolution of life on Earth characterized by the dominance of RNA (ribonucleic acid) molecules as the main players in genetic information storage, replication, and catalysis. This concept proposes that before the emergence of DNA and proteins, RNA may have been the "molecule of life."
In this scenario, it is believed that RNA molecules played a dual role as both genetic material, encoding information, and as functional molecules, catalyzing biochemical reactions. RNA possesses the ability to store genetic information because its linear sequence of nucleotides can be transcribed and translated into proteins. Moreover, certain RNA molecules, known as ribozymes, can also catalyze chemical reactions, just like enzymes, and participate in the replication of genetic material.
The RNA world hypothesis suggests that early life forms might have relied on self-replicating RNA molecules as the precursors of modern cells, predating the emergence of DNA-based genetic systems. It is thought that over time, DNA gradually took over the role of information storage, while proteins became more specialized in enzymatic and structural functions, relegating RNA to a more limited role in cellular processes.
While the RNA world is a theoretical model, numerous experiments and observations have provided evidence supporting the plausibility of this concept. Studying the properties and behaviors of RNA molecules has shed light on the early stages of life's origin and the evolutionary transition towards contemporary biological systems, leading to a deeper understanding of life's fundamental processes.
Etymology of RNA WORLD
The term "RNA world" was coined in 1986 by the molecular biologist Walter Gilbert. It is derived from the abbreviation "RNA" for ribonucleic acid, which is a molecule involved in various biological processes, including coding, decoding, regulation, and expression of genes. The concept of the RNA world refers to the hypothetical early stage in the evolution of life on Earth, where RNA molecules played a central role as both genetic material and catalytic molecules, before the emergence of DNA and proteins.
