Gene Expression Transcription PDF

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Summary

Lecture notes which cover transcription....

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Gene Expression TRANSCRIPTION Gene-Nucleotide sequences, hundreds or thousands of nucleotides long How do we go from a sequence of nucleotides ti a trait in an organism or a protein being produced “The central dogma” DNA (a polymer of nucleopeptides (A, G, T, C) in a specific order)->RNA(A process of going from one language to another in 2 fundamental steps)->Protein(A polymer of amino acids (alanine, glycine, etc) in a specific order CQ 59 B When a single pre mana molecule is made in on of your cells it contains the genetic code for one allele from one chromosome Gene expression = DNa directs the synthase of proteins -Two universal steps, transcription, translation TRANSCRIPTION Initiation-Figure out where to start reading DNA and actually begin making mRNA Elongation-Make the full length mRNA transcript Termination-Stop transcribing; mRNA completed CQ 62. Once polymerase binds it can only synthesize RNA in a 5 to 3 direction. Which of the two dNA strands shown here will it “ read” as it makes RNA - Read 3-5, synthesize 5-3 Genes are nucleotide sequences, hundreds or thousands of nucleotides long

With transcription factors in play, RNA polymerase can now bind DNA at the right place to begin transcription of the gene

Summary of Elongation in transcription

How do they stop? Bacteria: termination sequence vs Eukaryotes: A bit more complicated -Enzymes that cut the transcript free

-Another enzyme “Chases” RNA polymerase Before RNA leaves the nucleus, they are modified -Alteration of ends -Cutting out some of the middle -Offers the cell a way of controlling when nd where a protein is produced...