Controlling gene expression

What’s gene expression?

When a gene is transcribed and translated into a protein

What’s the second level of control of gene expression?

post-transcriptional level

What processes does primary mRNA need to undergo to become mature mRNA?

RNA splicing and RNA editing

What’s RNA splicing?

the removal of introns

What’s RNA editing?

when RNA bases are substituted, deleted or inserted

What’s the first level of control of gene expression?

transcriptional control

What’s a promoter?

a sequence of DNA that RNA polymerase binds to and through which begins the transcription process

What do prokaryotes have to control gene expression?

operators

What’s a repressor protein?

A protein which binds to the operator, stoping RNA polymerase from binding to the promoter and therefore stopping the transcription of structural genes

What produces the repressor protein?

The regulatory gene

What’s an operon?

A cluster of structural genes which is controlled by one promoter

What causes the lac operon to be active?

lactoses presence, causing lactase to be formed and for transcription to occur

How are transcription factors activated in a eukaryote?

by binding to a hormone

What does an active transcription factor do?

bind to the promoter and causes transcription to occur

what’s a transcription factor?

a protein which regulates the process of transcription

In prokaryotes do transcription factors inhibit or stimulate transcription?

inhibits

In eukaryotes do transcription factors stimulate or inhibit transcription?

stimulate

What’s the third level of control of gene expression?

post translational control

Whats post translational control?

changes the protein undergoes after translation to ensure that it can complete its function

What do proteins need to become in post-translational control for it to function?

activated

What does protein kinase bind to in phosohorylation

cyclic AMP

What does cyclic AMP do?

activate protein kinase

What does activated protein kinase do?

change the proteins tertiary structure and activates it

How can proteins be activated?

phosphorylation

What happens in phosphorylation?

cyclic AMP binds to protein kinase which activates the protein

Whats a body plan?

the observable spatial arrangement of an organisms body parts

What controls the formation of body plans?

mitosis and apoptosis

What does apoptosis cause?

cells to die

Whats mitosis?

the growth and devision of cells

What controls mitosis and apoptosis?

hox genes

What do hox genes respond to when deciding whether to stimulate mitosis or apoptosis?

internal (DNA damage) and external (stress) stimuli