BSC1010C Lecture Notes - Lecture 13: Peptide, Small Interfering Rna, Transcription Bubble
Document Summary
Transcription: is the synthesis of a strand of rna from a dna template. Mrna carries the coded information from dna to the ribosome, which is the site of protein synthesis trna, rrna use same mechanism of synthesis. Two ways the chemistry is different from dna synthesis: happens in a 5"-3" direction. Rna polymerase, uses ntps instead of dntps (dna): differences- only needs to open up a small bubble in the dna, don"t need an ever growing replication fork, since rna won"t be long term h-bonding to the dna. How do we know where the beginning of a gene is: dna replication: there is a designated sequence of bases (origin of replication)- tells the helicase enzyme where to start. Copy it all: transcription: only want to copy a small portion of the molecule. Need to know where to start and where to end. These two signals are both part of the dna sequence of a gene.
