Gene expression Flashcards
(15 cards)
Housekeeping genes
genes that are always needed
List the types of controls for gene regulation
transcriptional, posttranscriptional
translational
posttranslational
transcriptional
regulates which genes are transcribed or rate of transcription
DNA wrapped around histone
Activator molecules
post transcriptional
before leaving nucleus =, introns are removed
+ Alternate splicing
translational
length of time it takes for mRNA to be activated and the speed at which it’s destroyed
- Depend on length of poly A-tail
posttransitional
various chemicals are added to proteins that affect the rate of activity + how long it remains functional
what does the lac operon do?
help bacteria break down lactose for energy
What protein is used to control the transcription of B-galactosidase gene?
lacI protein`
B-galactosidase gene made of?
Z,Y,A
what is LacI protein
repressor protein that blocks transription
What does lactose act as
an effector
also a signal / inducer molecule
what is the effector in tryptophan
the effector
what happens when trp levels are high
the amino acid binds to repressor protein, altering its shape
what happens when trp levels are low
repressor protein changes shape
What is tryptophan called?
core repressor
