Cellular control Flashcards
What is the promoter region ?
where RNA polymerase binds
what binds to the operator region
repressor protein
what is regulatory gene
codes for repressor protein
what happens in lac operon when no lactose is present
- regulatory gene codes for repressor protein
- repressor protein binds to operator region + prevents RNA polymerase from binding to promoter region
- prevents transcription of structural genes so enzymes to metabolise lactose not made
what is a homeobox gene
a type of homeotic gene that contains homeobox (180 base pairs long ) + codes for homeodomain + controls position of body parts
hox genes
type of homeobox genes found in animals
where are homeobox genes highly conserved
in plants, animal and fungi
where do transcription factors bind
promoter region + either allow or inhibit transcription (activators or repressors)
what is post transcriptional control
pre- mRNA SPLICING
What is exon + what happens during splicing ?
exon codes for proteins + introns cut out , mRNA leaves nuclear pore to reach ribosomes for translation
what is post translational control + where does it occur
protein activation in golgi apparatus
6 stages of protein activation
- signalling molecule such as glucose binds to receptor on csm of target cell
- this activates G protein
- G protein activates adenyl cyclase
- ATP converted to cAMP catalysed by adenyl cyclase
- cAMP activates PKA
- PKA phophorylates/ activates other proteins
what happens when lactose is present
- lactose binds to repressor protein + changes repressors shape so it cannot bind to operator region
- so RNA polymerase binds to promoter region + transcribes structural genes
- enzymes to metabolise lactose made
