Gene Expression Flashcards
This RNA is responsible for coding proteins
mRNA
This RNA is responsible for positioning and holding the mRNA and TRNA during translation
rRNA
This type of RNA polymerase translates DNA to mRNA
RNA pol II
Epigenetic modifications do not change the DNA sequence but regulate whether genes are turned on or off. T/F
True
In order for RNA polymerase II to bind DNA, Histones must first be__________for binding sites to be exposed to DNA proteins
Separated
Nucleasomal arrangement is done by ___________binding a specific recognition sequence
Transcriptional enhancers
___________prevent transcription by forcing nucleosomal rearrangement such that RNA polymerase cannot bind the promoter
Repressors
__________causes an enhancer element that is far from from the promoter to interact with the initiation complex, stimulating transcription
DNA bending
The protein E2F is inactivated by________which represses transcription
Rb
When DNA is still in the B-form double stranded helix, with RNA polymerase and activating proteins bound to it, this is called the
Closed complex
When the RNA begins moving forward on the DNA , this is now called the
Open complex
This strand is the DNA equivalent to the mRNA produced
Coding strand
This strand is bound by RNA polymerase and is used for base pairing of nucleotides during transcription
Template strand
The growing RNA is assembles from_________to_______and is anti parallel to the template strand
5’; 3’
RNA polymerase required that Nucleosomes are________and that____________bind DNA, and that______bind regulators and the DNA at the start site
Moved out of the way
Transcription regulators
Transcription factors
The_______is a sequence of DNA found in the core promoter region of genes
TATA BOX
The TATA box is a non-coding region. T/F
True
The TFIIH protein has 2 enzymic activities. What are they?
Helicase activity
Kinase activity
The assembly of these proteins results in the closed complex of DNA
TBP
TFIIB
TFIIF
RNA POLYMERASE
TFIIE
TFIIH
The open complex is triggered by the Helicase activity of_______which also phosphorolates RNA polymerase
TFIIH
The carboxy terminal domain (CTD) of the large subunit of RNA polymerase II typically consists of___________which is involved with the initiation of transcription
52 repeats of Tyr-Ser-Pro-Thr-Ser-Pro-Ser
The phosphorylation of CTD is catalyzed by
TFIIH
The dephospha form of CTD binds to the________before getting phosphorolated
TATA box binding protein
The method of elongation initiation is done by the phosphorylation of_______via TFIIH which first recruits enzymes to the 5’ end and 3’ end, and then phosphorylation of_______activates elongation
Ser5;Ser2
Termination of elongation is done by
Dephosphorylation of RNA Pol II
________are sequences of RNA that will be retained and expressed while_________are sequences of RNA that will be removed
Exons; introns
The 5’cap is unique for
mRNA
tRNA and rRNA are made in the
Nucleus
Introns are recognized and folded into spliceosomes
The function of the 5’cap is to
Protect the 5’end of mRNA
Uniquely identify mRNA
The 5’cap is formed by the addition of_______to the 5’ phosphate via a triphosphate bridge
7-methyl-guanosine
Spliceosomes are complexes made up of
snRNPs (small nucleus ribonucleoproteins
The point at which introns are cut from the mRNA is called the
Lariat site
Splicing errors contribute to________of all diseases
1/3
DNA is replicated in the_______of the cell cycle
S phase
RNA can also form a helix structure within its structure. T/F
True
Amonioacyl-tRNA synthetase uses_______to charge the tRNA’s with an ________
ATP; amino acid
Amino acids are added to the_______end of tRNA
3’
Aminoacyl tRNA synthetase recognizes tRNA by the
CCA sequence
CCA is added to the 3’ end of tRNA by the enzyme
Nucletidyl transferase
The middle loop of the tRNA that encodes the complimentary sequence to the mRNA codon is called the
Anti codon loop
The genetic decode for start codons is
AUG
Stop codons are coded by
UAA, UAG, UGA
This mutation makes no difference
Silence
This mutation results in a different amino acid inserted that could change if properties of a protein
Missense
This mutation inserts a stop codon codon in the wrong location
Nonesense
This mutation adds or deletes bases in numbers which are not multiples of 3
Frameshift
Point mutations are
Single nucleotide changes
Point mutations are usually caused by
Deanimation or methylation of bases
Pre- Initiation of translation begins with the binding of_________to the 5’ cap of mRNAS
eIF4F
The eIF4F complex is composed of 3 subunits which is added soon after the 5’cap is added. What are they
eIF4E
eIf4A
eIF4G
eIF4A is a_______
Helicase
eIF4E is a
Cap binding protein
eIF4G is a
Docking protein
The eIF4F complexbinds to the______ribosomal subunit at the _______ carrying the mature mRNA with it
40s;eIF3
eIF2 is inactive when_______bound
GDP
When active, eIF2 binds with_________and Carries it to the 40s ribosome
Met-tRNA
eIF2 is phosphorylated by GTP, activating it, via
eIF2B
The first met-tRNA binds at which site
The P site
The second tRNA is carried to the_________via _______
A site; eEF1
________catalyzes hydrolysis of GTP which provides energy to move the tRNA from the A site to the P site
eEF2
Termination factors bind ribosome when a stop codon reaches the
A site
___________catalyzes the addition of an amino acid residue to grow the polypeptide chain
Peptides transferase
Translocation of the newly formed peptides tRNA from the A site to the Psite, while P site tRNA moves to the E site is done by
eEF2
Stop codons interact with
Release factors