BSCI 105 Lecture Notes - Lecture 23: Dna Replication, Nuclear Pore, Central Dogma Of Molecular Biology
Document Summary
Major differences in the pathway from gene to protein in prokaryotes and eukatyotes: unique features of eukaryotes. Rna is transcribed in the nucleus but translated in the cytoplasm. The transcript (pre-rna) contains large non-coding regions (introns) that are spliced out in the nucleus (rna processing) All of these steps are highly regulated. The regulation plays a major role in the regulation of gene expression. Molecular components of the transcription machinery: rna polymerase. Analogous to dna polymerase, helicase: promoter. Sie on dna where transcription is initiated. Eukaryotes: transcriptional initiation requires a tata box within the promoter and several proteins called transcription factors. Rna, rna polymerase and the transcription factors is called the transcription initiation complex: termination signal. In prokaryotes, this sequence is called the terminator. In eukaryotes, this signal is called the polyadenylation signal. Transcription in prokaryotes: in contrast to dna replication, only one strand of dna is transcribed.