Central dogma = dna into rna into protein that carries out particular function. Gene = stretch of dna in a genome that encodes a discrete and individual protein or rna. Operon is cluster of genes under same regulatory control. Monocistronic mrna is a single rna that codes for single protein. Polycistronic mrna is single rna that codes for multiple proteins. Regulons are operons around chromosome that share regulation. Regions of dna that control transcription of adjacent genes are called promoters. Promoter is region of dna that binds dna polymerase to initiate transcription of an adjacent gene. A -35 hexamer centered approximately thirty five nucleotides upstream of transcription. Up element rich in at base pairs. Consensus sequence of typical promoter determinants of promoter strength are sequences of the negative ten and negative thirty-five boxes and the amount of space between them: good promoter is reca. closest to census: bad promoter is arabad.