Central dogma- the directional flow of genetic information (genetic info transferred from dna to rna to protein. Rna polymerase binds to promoter regions of the dna, moves from the 3" to 5" end and will stop at the terminator. A consensus nucleotide sequence of tataat is at the 10th base pair of the 5" end and serves as part of the promoter region. They also have additional sequences that enhance the rate of transcription (ie. ttgcca about 35 nucleotides upstream) Sigma factors- proteins that facilitate the binding to the promoter region of the dna. Rho-independent- have a sequence and then the inverse of that sequence, which folds back on themselves to create a g-c rich hairpin loop. Rho-dependent- use a specific protein or rho factor, which can unstabilize the dna-rna transcript so that they dissociate from each other. Transcription and translation are coupled because they lack a nuclear envelope to separate the two.