Chapter 8 Control Gene expression

Does every cell have the same genome

yes

How does cell change gene expression

via external signals

How does is there regulation from RNA to mRNA

Splicing

Exporting of mRNA regulated

where it’s moved from different cell via the 3’ UTR and weather it’s degraded or not

What is translational control on mRNA

we can control when mRNA is translated

(it can exist outside of the nucleus but untranslated just sitting there waiting for it to be translated)

What is example of protein activity control

phosphorylation of protein to turn it on or off

How many different types of controls of protein activity/making is there

roughly 7

How does protein see within DNA

the protein does hydrogen bonding with it’s amino acid on the nitrogen base to recognize a specific sequence

What are transcription factors/regulators

things that promote transcription

Where does transcription factors bind too

DNA

What does transcription factor dimer do

increase specificity of binding to a specific sequence

How else is DNA observed

by being exposed, either it can be tightly coiled by nucleosomes/histomes or very loose and accessible

What is chromsome

DNA in it’s most packed states nothing can bind to DNA

What is ATP-Dependent chromatin remolding complex 

Enzymes that recognize a sequences bound to nucleosomes and unwinding them

What is histone acetyltransferase

Enzymes that recognize a sequences bound to nucleosomes and unwinding them

What does both ATP-Dependent chromatin remolding complex work

Binds to transcription regulator that sits on top of chromatin fiber and starts to unwind the chromatin fiber near by

How does histone acetyltransferase work

uses specific patter of histone acetylation to unwind that area

Is there long distance interaction with transcription factors in eukaryotic DNA

Yes

What does an Enhancers do

They increase probability of transcription working and rate, but they can be found thousands of base pairs away

How do enhancers reach promoter region

The DNA folds so they are closer together

What binds to enhancer region

an activator protein

What does an activator protein do

stabilize overall sequence that promotes transcription by binding to a mediator complex

What does a mediator complex do

acts as a mediator between activator protein and transcription factors to stabilize and start RNA polymerase

How is the loop between enhancer and promoter region created

by chromosome loop-forming clamp proteins (2 is needed)

How do some cells turn on transcription due to external stimuli

They have an activator protein that waits for an external stimuli to come in and bind to it to increase transcription

What 3 regulation factor make a cell act like a stem cell

Klf4, Sox2, Oct4

How does a cell get locked into their fate

Some times a gene makes a protein, that protein circles back increase transcription of that gene this allows cells to keep their identity even after dividing as the same process will occur

Is there memory from cell dividing

yes, because once you make a protein it can feedback and increase transcription (have to be an activator)

Why can’t you have a memory as a repressor

because it turns the “gene” off

Can regulatory activators/repressor regions change transcirption

yes because they will bind different transcription factors

What does miRNA do

they fold then a portion of it is broken down on each other than the RISC protein comes and unwinds it to make it single stranded

What does the miRNA and RISC complex do

if it all the bases pairs on miRNA and mRNA match then RISC + miRNA complex degrades the mRNA via nuclease found in RISC

if some of the base pairs from mRNA and miRNA align then mRNA gets either degraded or stuck so it can’t go through translation

What is RNA interference 

a defense mechanism with double stranded RNA is cleavage by dicer protein, and the small pieces pair with RISC to target viral RNA that initially hit

What is LncRNA

long non coding RNA it’s used to bind to protein to the bind to DNA