BIOL 2107K Lecture Notes - Lecture 3: Phosphodiester Bond, Chromatin, Cell Nucleus
Document Summary
Driven by nucleophilic attack on free hydroxyl, incoming phosphate. Topoisomerases help to coil and unwind coils to permit dna packaging and usage. Supercoils aid in maintaining the helical structure of a chromosome. Some sequences are more conducive to different environments. Transcription: synthesis of rna under the direction of dna (mrna) Translation: synthesis of a polypeptide under the direction of mrna. Rna types involved in transcription mrna trna rrna snrna (euk) microrna, sirna. Utr: leader sequence, contains a rna polymerase binding site. Promoter region on dna: where rna polymerase attaches and where initiation of rna begins. Rna polymerase (rnap): pries dna apart and hooks rna nucleotides together from the dna code. Terminator region: sequence that signals the end of transcription. Transcription unit: stretch of dna transcribed into an rna molecule. Initiation~ rnap binds to initiator sequence (tata box) Elongatio(cid:374)~ dna u(cid:374)wi(cid:374)ds, (cid:374)t added to the (cid:1007)" e(cid:374)d. The transcription bubble and driving transcription via high energy bonds.
