Biochem 27: Protein Metabolism

RNA carries authorisation. Protein metabolism executes the order.In this episode, Medlock Holmes follows genetic information to its most tangible outcome: proteins that are synthesised, folded, directed, deployed, and — when their work is done — dismantled. Translation is revealed not as a single event, but as the opening act in a carefully supervised lifecycle.Drawing on the integrative logic of Lehninger Principles of Biochemistry and the clinically grounded pathways in Harper’s Illustrated Biochemistry, we examine how ribosomes decode mRNA, how tRNAs enforce fidelity, and how newly made polypeptides are shepherded into correct folding and cellular destinations. Targeting signals, chaperones, and intracellular trafficking ensure that proteins arrive where they are needed — and nowhere else.Medlock also confronts the other half of the story: controlled destruction. Proteasomal degradation, ubiquitin tagging, and lysosomal pathways prevent accumulation, misfolding, and toxicity. Protein turnover is not wasteful; it is regulatory. Too much persistence is as dangerous as too little.Here, Medlock learns that protein metabolism is governance in motion — ensuring that the cell’s workforce is timely, localised, and accountable.Key Topics Explored* Translation and the genetic code* Ribosomal function and translational fidelity* Protein folding and chaperone systems* Targeting and intracellular trafficking* Ubiquitin–proteasome system* Lysosomal degradation and turnover* Clinical relevance: misfolding diseases and proteostasis failure 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