Gene regulation

constitutive gene

A gene that is always active, such as gyrase because its needed for DNA replication

transcriptional

regulates if the gene is transcribed or not

controls the rate of transcription

posttranscriptional

* modification of mrna
* chooses if spliceosomes are plenty or few, slowing the rate of processing (splicing out introns and splicing exons together)

translational

controls the rate of translation, how many tRNAs are present, if ribosome is fast enough, etc

controls rate of mrna activation degradation

posttranslational

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* Controls the rate at which a protein becomes active and the time it remains functional.

operon

* a cluster of genes regulated by the same promoter.

promoter

where RNA polymerase binds to the DNA for transcription

operator

where the repressor attaches

repressor

stops trancription because rna cant go past it

the lac operon

the one for lactose.

lac repressor

stops lactase being made

regulatory gene

the code before the promoter that makes the repressor molecule

allolactose

binds to the repressor, changes shape, and causes it to fall off

trp operon

the one for tryptophan