Basic difference between Lactose and Tryptophan operons
Lactose has an inducible operon (to induce catabolism), Trp has a repressible operon (to repress synthesis)

Products of lactose operon
B-galactosidase, lactose permease, thiogalactoside transacetylase

CAP
Catabolite Activator Protein; when glucose is low, CAP can bind with cAMP and the lac operon to start lactose catabolism

operator
adjacent to the transcription site, controls expression of operon

enhancer
regions of DNA that can be up to 1 kB upstream or downstream from the gene which bind proteins that affect gene transcription

prokaryotic transcription termination
rho-dependent (requires rho protein factor to disrupt RNA pol) and rho-independent (which relies upon formation of a stem-loop in the mRNA to disrupt RNA pol)

Trp attenuation
the mRNA can form alternate conformations: one with a stem-loop terminator that forms when Trp is plentiful; another anti-terminator conformation which forms when Trp is scarce and allows the transcription+translation to continue.

Differences in euk/prok transcription
1) Only 1 RNA pol in prok; multiple pols in euks;  2) prok RNA Pol binds directly to promoter region; Euk pols need transcription factors

Eukaryotic rRNA polymerase; location
RNA Pol I (Pol III for 5S subunit); nucleolus

Eukaryotic mRNA polymerase; location
RNA Pol II; nucleoplasm

Eukaryotic tRNA polymerase; location
RNA Pol III; nucleoplasm

Eukaryotic snRNA polymerase; location
RNA Pol III; nucleoplasm

Eukaryotic mRNA transcription steps
1) TFIID (composed of TBP which binds TATA, and TAFs); 2) TFIIB binds to TBP+DNA and forms a bridge to RNA Pol; 3) Pol II binds; 4) TFIIE and TFIIH join; 5) CTD of Pol II is phosphorylated;  6) Phos'd CTD releases Pol II; 7) Mediator and other factors join; 8) Transcription proceeds

Eukaryotic promoters
TATA box, Inr sequence