CHEM 282 Lecture Notes - Lecture 4: Ribosomal Rna, Start Codon, Dna Replication
19 Apr 2021
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1. 5% of the genome codes for protein but 85% of the genome is transcribed (made into. Rna) snrnas form part of the spliceosome that is important for mrna processing snornas are involved in modifying the ribosome and are well understood. Micrornas and long coding rnas are involved in a variety of cellular regulatory processes. Rna polymerase transcription is catalyzed by the enzyme rna polymerase. Transcription is similar to dna replication as it is performed in the same direction and requires a template strand, however rna polymerase doesn"t require a primer to begin synthesis. Prokaryotes have one rna polymerase, rna pol, which is very similar in structure to the 3 eukaryotic rna polymerases. The bacterial rna pol 1 has a five-polypeptide subunit core with 3 distinct subunits and two alpha subunits. The five subunits core must associate with a coenzyme subunit called the sigma factor which acts as a transcriptional initiating factor and adds dna binding selectivity.
