BIOL 3090 Midterm: Exam 2 Notes (scored 92%)
Document Summary
Most rnas are single stranded (cid:224) mrna and rrna are single: stem is the double stranded region, standard base pairing occurs in the stem, stem loops formed by pairing of bases that are separated by 10 or more nucleotides. Initiation of transcription: during transcription initiation, rna polymerase recognizes and binds to a specific site called a promoter with in double stranded dna, rna polymerase requires transcription factor, initiation is considered complete when the first two ribonucleotides of an rna chain are linked by a phosphodiester bond. Termination: rna polymerase continues until sequence is reached, completed rna molecule is the transcription termination called the primary transcript, model for bacterial rna polymerase as it synthesizes rna. Gene organization in eukaryotic cells: separate genes, scattered throughout the genome for the five necessary for tryptophan biosynthesis, there are no polycistronic mrnas in eukaryotes, all five tryptophan genes are coordinately regulated (cid:224) they same time, bacterial operon is more efficient than eukaryotic system.
