lac operon
What is absent?
No tryptophan present = trp operon is ____
What is on?
These organisms commonly use operons
What are prokaryotes?
These DNA sequences reduce transcription initiation
What are silencers?
This term refers to genes that code for the primary structure of an enzyme or protein
What are structural genes?
Maximum lac operon transcription happens when these two conditions are met
What are lactose present and glucose absent?
The trp operon is an example of this type of system
What is repressible?
Gene regulation is more complex in these cells
What are eukaryotic cells?
These proteins increase transcription initiation
What are activators?
This type of control requires a regulator molecule to stimulate transcription
What is positive control?
This gene codes for β-galactosidase
What is lacZ?
This protein binds to the operator when activated by tryptophan
What is the trp repressor?
What is splicing?
DNA methylation usually has this effect on gene expression
What is decreased?
A single mRNA that codes for multiple proteins is called this
What is polycistronic mRNA?
When glucose is absent, this molecule rises and helps CAP bind
What is cAMP?
In prokaryotes, attenuation is possible because these two processes happen simultaneously
What are transcription and translation?
These proteins package DNA in eukaryotes
What are histones?
In eukaryotes, these are non-coding segments of DNA or RNA that regulate the expression of genes or operations on the same molecule
What are cis-acting sequences?
This term describes enzymes made continuously regardless of the environment
What are constitutive enzymes?
What is constitutive expression?
During attenuation, transcription is stopped after the formation of this structure
These cells can respond rapidly to environmental change through gene regulation
What are prokaryotic cells?
Adding acetyl groups to histones usually does this to transcription
What increases transcription?
This operon is regulated by a protein that can both activate and repress transcription
What is the ara operon?