Biochem 26: RNA Metabolism

DNA may hold the master record, but it rarely speaks directly. In this episode, Medlock Holmes follows information as it leaves the archive — transcribed into RNA, reshaped, edited, and prepared for use.RNA metabolism reveals a striking principle: information is not simply copied; it is curated. Transcription initiates the process, but splicing, modification, transport, and degradation determine what ultimately reaches the cellular machinery. The same gene can give rise to multiple messages, each shaped by context, timing, and need.Drawing on the conceptual clarity of Lehninger Principles of Biochemistry and the clinically grounded treatment of RNA synthesis and processing in Harper’s Illustrated Biochemistry, this episode explores mRNA, tRNA, rRNA, and regulatory RNAs as distinct but coordinated actors. Control is exerted not only at transcription, but at every subsequent step.Medlock learns that RNA metabolism introduces flexibility into an otherwise rigid system. It allows cells to respond rapidly without rewriting the genome. Disease emerges when this flexibility becomes distortion — when splicing fails, messages degrade prematurely, or regulation is lost.Here, information becomes provisional — authorised for use, but never permanent.Key Topics Explored* Transcription and RNA polymerases* RNA processing: capping, splicing, polyadenylation* Alternative splicing and transcript diversity* Roles of mRNA, tRNA, rRNA, and regulatory RNAs* RNA transport, stability, and degradation* Clinical relevance: splicing disorders and gene expression defects This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit drmanaankarray.substack.com/subscribe