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Flashcards in Chapter 3 - Genetics Deck (191)
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181

structural genes

sequences of DNA that code for proteins

182

operator gene

sequence of nontranscribable DNA 

repressor binding site

183

repressor

 DNA-binding protein

regulates the expression of one or more genes

binds to the operator and blocks the attachment of RNA polymerase to the promoter

preventing transcription of the genes

184

promoter

noncoding sequence 

intial binding site for RNA polymerase

185

regulator gene

codes for synthesis of a repressor molecule

186

in order to transcribe structural genes, RNA polymerase must

move past operator

187

regulatory systems function

prevent or permit RNA polymerase to pass on to structural genes

188

modes of regulation

inducible systems

repressible systems

189

inducible system 

basic

(transcription - bacterial genetics)

require presence of inducer

190

repressible system

basic

(transcription - bacterial genetics)

in constant state of transcription

unless corepressor inhibits 

191

inducible systems

mechanism

repressor binds to operator

forms barrier that prevents RNA polymerase from transcribing structural genes