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Biochemistry Exam 1
Tufts University School of Medicine M1 Biochemistry
200
Medical
Graduate
09/14/2008

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Term
Condensed, transcriptionally inactive chromatin
Definition
heterochromatin
Term
Less condensed, transcriptionally active chromatin
Definition
euchromatin (Eu = true, 'truly transcribed')
Term
Which nucleotides have 2 rings?
Definition
Purines (A, G)

PURe As Gold
Term
Which nucleotides have 1 ring?
Definition
Pyrimidines (C, T, U)

CUT the PY
Term
Nucleotides are linked by:
Definition
3' - 5' phosphodiesterase bond
Term
substituting a purine for a purine or a pyrimidine for a pyrimidine
Definition
transition

(transItion = Identical type)
Term
substituting a purine for pyrimidine or vice versa
Definition
transversion

(transversion = conVersion between types)
Term
4 features of the genetic code:
Definition
unambiguous - each codon specifies only 1 amino acid

degenerate - more than 1 codon may code for the same amino acid

commaless, nonoverlapping (except in some viruses)

universal (exceptions include mitochondria, archaeobacteria, Mycoplasma, and some yeasts)
Term
Rank the following mutations in severity of damage: missense, silent, nonsense
Definition
nonsense > missense > silent
Term
Prokaryotic DNA replication and DNA polymerases:

Single origin of replication - continuous DNA synthesis on leading strand and discontinuous (______ fragments) on lagging strand.

_____ makes an RNA primer on which _____ can initiate replication. The previously mentioned enzyme elongates the chain by adding deoxynucleotides to the __ end until it reachers the primer of preceding fragment.

5'->3' exocnuclease activity of _____ degrades the RNA primer. ______ seals.
Definition
Okazaki fragments
Primase
DNA polymerase III
3'
DNA polymerase I
DNA ligase
Term
DNA polymerase III has __ -> __ synthesis and profreads with __ -> __ exonuclease.
Definition
5' -> 3'
3' -> 5'
Term
DNA polymerase I excises RNA primer with __ -> __ exonuclease.
Definition
5' -> 3'
Term
DNA polymerase III has __ -> __ exonuclease activity to 'proofread' each added nucleotide.
Definition
3'->5'
Term
_________ create a nick in the helix to relieve supercoils
Definition
DNA topoisomerases
Term
name the DNA polymerases for synthesizing:
RNA primers
leading-strand DNA
lagging-strand DNA
mitochondrial DNA
and DNA repair
Definition
alpha
beta
gamma
delta
epsilon
Term
DNA repair: single strand

Single-strand, excision repair-specific glycosylase recognizes and removes damaged base. ____ makes a break several bases to the 5' side. _____ removes short stretch of nucleotides. DNA polymerase fills the gap and DNA ligase seals.
Definition
Endonuclease
Exonuclease

(EXonuclease = EXcision)
Term
DNA repair: double strand

If both strands are damaged, repair may proceed via _____ with undamaged homologous chromosome.
Definition
recombination
Term
Name 4 diseases caused by DNA repair defects
Definition
Xeroderma pigmentosum (skin sensitivity to UV light)

ataxia-telangiectasia (x-rays)

Bloom's syndrome (radiation)

Fanconi's anemia (cross-linking agents)
Term
DNA / RNA / protein synthesis direction
Definition
DNA and RNA both 5'->3'
(Remember that the 5' of the incoming nucleotide bears the triphosphate (energy source for bond). The 3' hydroxyl of the nascent chain is the target. Imagine the incoming nucleotide bringing a gift (triphosphate to the 3' host. "BYOP (phosphate) from 5 to 3.")

Protein synthesis also proceeds in 5' to 3' direction, and amino acids are linked N to C.
Term
Name the three types of RNA and a quality of each
Definition
mRNA is largest type of RNA
rRNA is the most abundant type of RNA
tRNA is the smallest type of RNA

(Massive, Rampant, Tiny)
Term
In eukaryotes:

RNA polymerase I makes
RNA polymerase II makes
RNA polymerase III makes

alpha-amantin inhibits:
Definition
rRNA
mRNA
tRNA

(I, II, and III are numbered as their products are used in protein synthesis)

alpha-amantin inhibits RNA polymerase II and slightly inhibits III.
Term
Start codon is:
Stop codons are:
Definition
AUG

(AUG inAUGerates protein synthesis)

UGA, UAA, UAG
(U Go Away, U Are Away, U Are Gone)
Term
in Eukaryotes, AUG codes for which amino acid which may be removed before translation is completed?
Definition
methionine
Term
in prokaryotes, AUG codes for what amino acid?
Definition
formyl-methionine (f-met)
Term
Site where RNA polymerase and multiple other transcription factors bind to DNA upstream from gene locus.
Definition
promoter

(promoter mutation commonly results in dramatic decrease in amount of gene transcribed)
Term
Stretch of DNA that alters gene expression by binding transcription factors. May be located close to, far from, or even within (in an intron) the gene whose expression it regulates).
Definition
enhancer
Term
Introns vs. exons
Definition
INtrons stay IN the nucleus (and are INtervening sequences)

EXons EXit and are EXpressed
Term
_____ facilitate splicing by binding to primary mRNA transcripts and forming spliceosomes
Definition
smal ribonucleoprotein particles (snRNP)
Term
Initial RNA transcript (unprocessed) is known as _______.

The capped and tailed transcript is called _____.
Definition
heterogenous nuclear RNA (hnRNA)

mRNA
Term
RNA processing (eukaryotes only):

1)___________
2)___________
3)___________
Definition
1) capping on 5' end (7-methyl-G)
2) polyadenylation on 3' end (about 200 A's)
3) splicing out of introns

(Only processed RNA is transported out of the nucleus)
Term
tRNA STRUCTURE:

75-90 nucleotides,
cloverleaf form
anticodon end is opposite 3' aminoacyl end. All tRNAs, both eukaryotic and prokaryotic, have ___ at 3' end along with a high percentage of chemically modified bases. The amino acid is covalently bound to the __ end of the tRNA
Definition
CCA

3'
Term
Aminoacyl-tRNA synthetase (1 per aa, uses ATP) scrutinizes aa before and after it binds to tRNA. If incorrect, bond is hydrolyzed by synthetase. The aa-tRNA bond has energy for formation of peptide bond. A mischarged tRNA reads usual codon but inserts wrong amino acid.
Definition
Aminoacyl-tRNA synthetase and binding of charged tRNA to the codon are responsible for accuracy of aa selection.
Term
energy is required for what stages of protein synthesis?
Definition
charging
(ATP - tRNA Activation)

translocation

(GTP - tRNA Gripping and Going places)
Term
Match RNA, DNA, protein to Western, Northern, Southern blot:
Definition
SNoW DRoP

Southern = DNA
Northern = RNA
Western = Protein
Term
A rapid immunologic technique in which an antibody or an antigen is coupled to an enzyme as a means of detecting an antigenic match -- it is a test of antigen-antibody reactivity. The test challenges patients' blood samples either with an antigen to see if their immune system recognizes it or with an antibody to see whether a particular antigen is present in the sample. If the target substance is present in the sample, the test solution will have an intense color reaction indicating a positive result.
Definition
Enzyme linked immunabsorbent assay (ELISA)

(ELISA is used in many laboratories to determine whether a particular antibody (e.g. anti-HIV) is present in the patient's blood sample. Both the sensitivity and specificity of ELISA approach 100%, but both false positive and false negative results do occur.)
Term
Small subunit of eukaryotic ribosome made of protein and RNA made by ______.
Definition
RNA Polymerase I
Term
Large subunit of ribosome (60S) composed of lots of _______ and _____ made from pol I, along with an oddball made by ______.
Definition
proteins, RNAs, RNA polymerase III
Term
Initiation of protein synthesis starts on ____ subunit.
Definition
Small subunit
Term
The genetic code was broken using a _________ system.
Definition
cell free protein synthesizing system
Term
How many nucleotides are in a tRNA?
Definition
about 80
Term
tRNAs contain many bases that are _______
Definition
modified
Term
A ribosome knows that a piece of mRNA is meant to be translated because it has a ____
Definition
5' cap
Term
An mRNA's 5' cap is recognized by _______.
Definition
cap binding protein
Term
What three molecules form a complex with the 40S ribosomal subunit prior to the start of transcription?
Definition
eIF2-GTP-Met-tRNA
Term
which factors must fall off in order for the 60S subunit to bind with the 40S subunit?
Definition
eIF2-GDP
Term
What catalyzes GTP-dependent binding of aminoacyl-tRNA to ribosomes (docks tRNAs)?
Definition
Elongation Factor 1 (EF1)
Term
Which factor is required for moving mRNA through ribosome? This is GTP-dependent.
Definition
Elongation factor 2 (EF2)
Term
Where are uncoding regions in a eukaryotic mRNA found?
Definition
At both 3' end and 5' end (termination happens before the end of mRNA)
Term
How many proteins are produced per mRNA in eukaryotes?
Definition
1
Term
what is it called when there are multiple ribosomes translating the same mRNA at the same time?
Definition
a polyribosome (occurs in both prokaryotes and eukaryotes)
Term
How is a start AUG distinguished from an AUG in the middle of a gene in prokaryotes?
Definition
the shine-dalgarno sequence (a region of the 3' terminus of the 16S ribosomal RNA that is complementary to translation initiation sites).
Term
The first amino acids that are translated on a protein that is destined for secretion in eukaryotes are known as the _______.
Definition
signal peptide
Term
the signal peptide is recognized by the _____, which stops translation temporarily.
Definition
signal recognition protein (SRP)
Term
After being inserted through the ER membrane, the signal peptide is cleaved by _________.
Definition
signal peptidase
Term
What sequences anchor proteins in a membrane during translation?
Definition
Stop transfer membrane anchor sequences
Term
Name 2 examples of proteins that are formed through alternative splicing.
Definition
alpha-tropomyosin (involved in muscle contraction)

antibodies (membrane bound vs. floating around)
Term
A poly(A) tail, normally located at the end of an mRNA, may be found in the middle due to __________.
Definition
Alternative splicing
Term
the poly A tail on an mRNA is able to regulate protein synthesis by controlling ________.
Definition
how fast the mRNA decays
Term
name an example of a very unstable mRNA that decays very quickly because they have short (or practically no) poly A tails.
Definition
histone mRNAs
Term
mRNA stability can be affected by _______ and _______ in addition to the length of its polyA tail.
Definition
hormones and nutrients
Term
What step is most regulated in the regulation of protein synthesis?
Definition
the initiation step
Term
When regulating protein synthesis, the cell can phosphorylate ______ to deactivate it and thus stop overall protein synthesis.
Definition
eIF-2 (eukaryotic initiation factor 2)
Term
Name three things that could cause phosphorylation of eIF-2 in order to stop protein synthesis?
Definition
viral infection
heme deprivation or heat shock
amino acid starvation
Term
What compound inhibits bacterial and eukaryotic protein synthesis by releasing the nascent polypeptide chain? It resembles the terminal portion of t-RNA, so it goes to the A site and binds to the growing polypeptide, cutting it off.
Definition
puromycin

(pure and innocent looking because it resembles the tRNA, but really it is evil and can trick both prokaryotes and eukaryotes)
Term
What compound inhibits peptidyl transferase in prokaryotic ribosomes?
Definition
Chloramphenicol

(like a doctor who is on call and has to leave his wife at night, chlorampheniCOL stops the reaction that forms a bond from happening)
Term
What compound inhibits binding of the formyl-methionine-tRNA to the 30S subunit in prokaryotes?
Definition
Streptomycin

(Just like you wouldn't want to INITIATE making out with a girl who has STREP throat, STREPtomycin prevents INITIATION of protein synthesis)
Term
What compound binds to the 30S subunit and inhibits the binding of aminoacyl-tRNAs (to the A site) in prokaryotes?
Definition
Tetracycline

(TetrAcycline inhibits binding of Aminoacil-tRNAs to the A site)
Term
What compound binds to the 50S ribosomal subunit in prokaryotes and blocks translocation?
Definition
Erythromycin

(eRYTHmorycin stops the RHYTHMic movement of the mRNA through the ribosome because it blocks the translocation step)
Term
What compound inhibits eukaryotic peptidyl transferase?
Definition
Cycloheximide

(riding on a uniCYCLE puts a HEX on your love life and any chance of forming a BOND with a woman, in the same way that chloramphenicol also prevents bond formation... the more sophisticated mnemonic points to this being a eukaryotic inhibitor)
Term
A toxin that inactivates EF-2 is...
Definition
diptheria toxin

(rhymes with hysteria... mass hysteria stops any ordered movement from happening, the same way diptheria toxin stops ordered movement of the mRNA through the ribosome)
Term
A single point mutation can alter the splicing activity of an mRNA (knocking out splice sites or adding them in) by activating ________.
Definition
cryptic splice sites.
Term
Expression of recombinant proteins requires that their _____ be converted into _____.
Definition
mRNA, cDNA
Term
Name the polar and neutral amino acids (4)
Definition
threonine, serine, glutamine, asparagine

THRee are SERenely GLUINg ASParagus
Term
Name the polar and charged amino acids (5)
Definition
histidine, lysine, arginine (positive)

glutamate, aspartate

HIS LYCe ARE GLUing ASParagus
Term
Name the hydrophobic amino acids (9)
Definition
Isoleucine, methionine, valine, alanine, leucine, tyrosine, tryptophan, phenylalanine, proline

I MET VAL and AL as LEU and TYRone took a TRYP over the PHEnway like PROs.
Term
When two amino acids form a peptide bond a _____ molecule is lost.
Definition
Water
Term
An example of a medicine which is dependent on stereoisomerism is ______
Definition
isoproterenol (a bronchodilator)
Term
What are the three possibilities of a mutation's effects on protein?
Definition
no effect
affect function but not structure
affect structure (stability) and function
Term
Show how the NH3+, COOH, and COOH groups of glutamate change as the pH increases.
Definition
NH3+ and COOH and COOH <--pKa1--> NH3+ and COO- and COOH <--pKaR--> NH3+ and COO- and COO- <--pKa2--> NH2 and COO- and COO-
Term
What are the only ionizable groups in a peptide chain?
Definition
side chains and the ends of the chain
Term
What is a problem with SDS-PAGE analysis of proteins?
Definition
SDS destroys protein function and is hard to remove
Term
histidines, arginines, and lysines are commonly in what functional domain of a protein?
Definition
DNA binding domain
Term
______ weakens protein interactions
Definition
salt
Term
changing the______ will alter the net charge of a protein, allowing to elute from an ion exchange column.
Definition
pH
Term
what is the problem with metabolic acidosis with respect to proteins?
Definition
they cannot function at lower pHs!

(chloride channels shut down at higher and lower pHs than optimal)
Term
The combination of base and sugar is called a ________.
Definition
nucleoside
Term
In notation used for DNA, a p to the left of a base indicates a ________ linkage.
Definition
5'
Term
The hydrophobic bases are pointed toward the (outside / inside) of a DNA double helix?
Definition
inside
Term
The phosphate group in DNA are very ________ charged and point towards the outside of the helix.
Definition
negatively
Term
If twists are introduced in the same direction as the winding of DNA double helix, the DNA molecule is ________.
Definition
positively supercoiled
Term
This enzyme cleaves one strand of a DNA helix, passes DNA around the breaks, and reseals the DNA breaks.
Definition
Topoisomerase I
Term
This enzyme cleaves both strands of a DNA helix, passes DNA around the breaks, and reseals the DNA breaks.
Definition
Topoisomerase II
Term
This drug inactivates Topo I
Definition
camptothecin

(Topo I is an unruly young child that must 'inactivated' by being sent to summer camp)
Term
This antitumor drug inhibits Topo II
Definition
m-AMSA

(Topo II is the mom enzyme. M-AMSA makes MOM SAD)
Term
A left-handed DNA double helix is known as __________.
Definition
Z-DNA
Term
__________ repeats in DNA are especially prone to bending
Definition
adenine
Term
Polypurine/polyperimidine tracts can form __________ DNA.
Definition
triple-helical DNA (H-DNA)
Term
How many base pairs are in the human haploid genome?
Definition
3 x 10^9
Term
How many genes are in a human?
Definition
~30,000
Term
An example of a set of genes that appears to have arose from duplication and variation from an ancestral gene is the _________ located on chromosome 11.
Definition
beta-globin gene cluster
Term
What percent of our genome encodes proteins?
Definition
1-2%
Term
Sequences that are closely related to functional genes but no longer code for normal gene products are called __________.
Definition
pseudogenes
Term
This class of pseudogenes is formed when DNA copies of RNA molecules are inserted back into an organism's genome.
Definition
processed pseudogenes
Term
Sequences capable of inserting copies of themselves into new genomic locations are called:
Definition
transposable elements
Term
A class of transposable elements that are less than 500 nucleotides long and transpose through reinsertion of their products of reverse transcription
Definition
Short, interspersed repeat elements (SINEs)
Term
A class of transposable elements that are more than 500 nucleotides long and transpose through reinsertion of their products of reverse transcription
Definition
long, interspersed repetitive elements (LINEs)
Term
An example of a SINE family that composes about 10% of human DNA.
Definition
Alu family
Term
An example of a LINE family, this one contains as many as 500,000 copies.
Definition
L1 family
Term
A member of a class of transposable elements that transpose directly through DNA copies and encode their own transposase.
Definition
Simple Sequence Repeats (SSRs)
Term
Arrays of short (2-5 bp) nucleotide repeats.
Definition
microsatellites
Term
variable number of tandem repeats (VNTRs) are also known as _______. They have repeat units of 14-500 bases.
Definition
minisatellites
Term
A place in DNA where common variances occur is called a ___________.
Definition
polymorphism
Term
A member of a class of transposable elements that transpose directly through DNA copies and encode their own transposase and has repeat units varying from 5-100 bps (and are usually located on untranscribed regions of DNA like centromeres and telomeres).
Definition
satellite sequences
Term
a core group of 8 histones with DNA wrapped around them is known is a ______
Definition
nucleosome
Term
nucleosomes are ordered into _______ fibers.
Definition
chromatin
Term
This protein prevents reannealing of DNA strands during DNA replication.
Definition
single strand binding protein (RPA)
Term
Origin recognition in humans is dependent upon a group of proteins termed ______.
Definition
the origin replication complex (ORC)
Term
A DNA helicase is deficient in children with __________ (significant risk of developing malignancies)
Definition
Bloom's syndrome
Term
A DNA helicase deficiency that causes premature aging.
Definition
Werner's syndrome
Term
The leading strand is formed by
Definition
pol delta or epsilon
Term
pol delta and epsilon have a 3' to 5' _______ activity
Definition
exonuclease
Term
What enzyme cleaves individual nucleotides from the ends of polynucleotide chains?
Definition
an exonuclease
Term
The RNA primer in lagging strands is placed by
Definition
polymerase alpha (pol-alpha primase)
Term
_____ is the only polymerase known to be associated with a primase
Definition
pol alpha
Term
After synthesis of the primer in lagging strands, the DNA nucleotides are placed by
Definition
pol delta or epsilon
Term
This auxiliary factor locks polymerases onto DNA
Definition
Proliferating Cell Nuclear Antigen (PCNA)
Term
This auxiliary factor loads pol sigma and epsilon onto DNA
Definition
Replication factor C (RFC)
Term
This polymerase is responsible for mitochondrial DNA synthesis
Definition
polymerase gamma
Term
This polymerase is believed to play a role in certain repair events
Definition
polymerase beta
Term
A nucleotide analogue used to treat HIV is known as
Definition
AZT
Term
The cell cycle engine is assembled from _____
Definition
protein kinases
Term
Progress through the cell cycle is regulated closely by a number of closely related molecules that are a complex of at least 2 proteins: a kinase and a cyclin.
Definition
cyclin-dependent protein kinases (Cdk)
Term
This protein functions as a cell cycle checkpoint at the G1/S checkpoint. When damaged DNA is detected, it arrests the cell cycle.
Definition
p53
Term
More than half of all human malignancies diagnosed each year have a mutated or missing ______ allele
Definition
p53
Term
In DNA mismatch repair in E.Coli, the mismatched bases are recognized by a protein termed ______
Definition
Mut S

(Mut S SenSeS)
Term
In DNA mismatch repair in E.Coli, the strand excision is catalyzed by a protein termed ______
Definition
Mut H

(Mut H Hacks and Hews DNA)
Term
n DNA mismatch repair in E.Coli, a protein-protein interface between Mut H and Mut S is thought to be achieved by a protein termed ______
Definition
Mut L

(Mut L Links)
Term
The human Mut S and Mut L homologues are called:

________
________
Definition
hMSH
hMLH

(human mut S homologue! note that hMHH has not been isolated because this just sounds weird)
Term
People who contain CAG repeats above the normal range in a certain gene are at risk of developing....
Definition
Huntington's disease
Term
The following are the 4 steps for _________.

1)incision
2)excision
3)resynthesis
4)ligation
Definition
excision repair
Term
In E. Coli, pyrimidine dimers that are to be repaired through excision repair are recognized by a complex known as
Definition
uvrABC

(ultra violet repair, a big complex)
Term
In E. Coli, this enzymes resynthesizes DNA that is excised by uvrABC during excision repair:
Definition
DNA polymerase I (pol I)
Term
When cytosine spontaneously deaminates to form uracil, ______ is the enzyme that comes to the rescue by recognizing and hydrolyzing the bonds.
Definition
uracil-DNA glycosidase

(cuts the glycosidic bond)
Term
sites where bases are removed are called ____
Definition
AP sites

(APurinic or APyrimidic... isn't it nice that they both start with P??)
Term
Nitrous acid reacts with basis that contain amino groups to cause
Definition
deamination
Term
the N7 position of guanine is particularly prone to (this is bad) ______
Definition
alkylation
Term
name 2 molecules that intercalate between DNA
Definition
proflavin and ethidium bromide

(proflavin means it has a delicious flavor like an unhealthy cake, which DNA is tempted too. Unfortunately, this compound fucks up DNA)
Term
A n-base cutter will have a cut site on average once every __ nucleotides
Definition
4^n
Term
variability of the human genome allows genetic examination of _______
Definition
restriction fragment length polymorphisms (RFLPs)
Term
RFLPs can be caused by two types of DNA variations:

___________
___________
Definition
single base changes and
tandem repeats of base sequences
Term
A strategy of detecting mutations through hybridization requires __________
Definition
allele-specific oligonucleotide probes (ASOs)
Term
A modification of PCR that allows one to determine whether a specific RNA molecule is present in a sample
Definition
RT-PCR
Term
A method that seperates DNA strands in a gel based on their conformation
Definition
Single-strand conformation polymorphism (SSCP)
Term
An enzymatic method for determining the sequence of a DNA molecule
Definition
Sanger method
Term
nucleotides that lack both the 2' and 3' hydroxyl groups on the ribose and are used in the Sanger method are known as
Definition
ddNTPs
Term
A simple assay used to determine if a protein interacts with a particular DNA fragment
Definition
DNA Band Shift
Term
Detailed information about protein-DNA interactions can be obtained by a technique known as the __________
Definition
DNase I footprinting assay
Term
A DNA library constructed directly from genomic DNA and used to isolate specific fragments of genomic DNA
Definition
genomic library
Term
A DNA library derived from mRNA
Definition
cDNA library
Term
A method that uses VNTRs to identify the source of different DNA samples is known as
Definition
DNA fingerprinting
Term
What is the only RNA polymerase located inside the nucleolus?
Definition
RNA polymerase I
Term
What units, transcribed by RNA pol I, are arranged in multiple, tandemly arrayed copies in the genome?
Definition
rRNA transcription units
Term
RNA polymerase I requires what 2 factors to bind to DNA and transcribe rRNA genes??
Definition
factor B and S factor

(does anyone else think it's BS that we have to memorize factor B and S factor??)
Term
What is special about the activation region for the transcription of 5S rRNA by Pol III?
Definition
it lies within the gene
Term
What transcription factor first binds to the regulatory region of the 5S rRNA gene?
Definition
TFIIIC

(TFIIIC Clears the area for Binding of TFIIIB)
Term
What transcription factor is recognized by pol III but can only bind DNA when TFIIIC has bound?
Definition
TFIIIB

(TFIIIB is the Bitch because TFIIIC always has to bind first)
Term
The sole highly conserved sequence utilized during RNA pol II transcription is the
Definition
TATA box
Term
What transcription factor binds to the TATA box region?
Definition
TATA Binding Protein (TBP)
Term
TATA binding protien is a subunit of what basal transcription factor?
Definition
TFIIID

(TFIII D is the only basal transcription factor that binds to DNA)
Term
What is the most invariable element in a polyA site?
Definition
the AAUAAA sequence
Term
The AAUAAA sequence is bound by the
Definition
cleavage and polyadenylation specificity factor (CPSF)
Term
What sort of columns can easily remove mRNA from a mixture of cell products
Definition
an oligo (dT) column
Term
the hairpin loop created by reverse transcriptase during production of a cDNA library can be cleaved by this enzyme ______
Definition
S1 nuclease
Term
name 2 ways to screen colonies in a library for cDNA clones of interest:
Definition
nucleotide probes complementary to the cDNA

check if an expression vector was used during cloning -- in this case, antibodies can be used against the protein expressed by the desired cDNA
Term
gene sites that are very accessible to enzymes such as DNAse I and are found in upstream control regions are called
Definition
hypersensitive sites
Term
The expression of gene families can be regulated by an element acting over long distances known as _______________
Definition
the Locus Control Region (LCR)
Term
Protein complexes such as SWI-SNF that can alter chromatin structure are said to be involved in the process of __________
Definition
nucleosome remodeling
Term
Acetylation of histones leads to their activation or deactivation?
Definition
activation
Term
Methylation of certain __ residues may be part of the process that keeps some genes in the inactive state
Definition
C
Term
Activators communicate to the basal factors through
Definition
coactivators
Term
Activators bind to regulatory regions of DNA known as
Definition
enhancers
Term
This protein is normally present in cells and is activated when temperature is increased dramatically. It then binds to DNA and is phosphorylated, causing transcription of certain genes.
Definition
heat-shock factor
Term
Current DNA microarrays contain how many genes?
Definition
~10,000
Term
Microarray

normal cells: green dye
transformed cell: red dye

What color will spot be if there is no difference in gene expression?
Definition
yellow
Term
Microarray

normal cells: green dye
transformed cell: red dye

What color will spot be if there is more transcription of a particular gene in the transformed cell?
Definition
red
Term
Microarray

normal cells: green dye
transformed cell: red dye

What color will spot be if there is more transcription of a particular gene in the normal cell?
Definition
green
Term
Microarray

normal cells: green dye
transformed cell: red dye

What color will spot be if a given cDNA is not present in either cell type?
Definition
black
Term
One conclusion of DNA microarray studies was that the oncogene _____ is expressed at abnormally high levels in malignant breast tumor cells.
Definition
ErbB2

('Error in breast?')
Term
Introduction of a nucleic acid complementary to an aberrantly expressed mRNA to prevent its translation is an experimental therapy known as
Definition
antisense therapy
Term
The mechanism of sequence-specific, post-transcriptional gene silencing initiated by double-stranded RNAs homologous to the gene being suppressed is called
Definition
RNAi
Term
this initiation factor interacts with the mRNA molecule before translation by associating with the m7G cap structure.
Definition
eIF4F

(associates with G cap. What is the letter before G? F. eIF4(Four)F)...)
Term
Activation of each t-RNA requires __ high energy phosphate bonds
Definition
2 (since ATP --> AMP)
Term
An example of a very stable mRNA that decays very slowly is the mRNA for
Definition
albumin (also hemoglobin)
Term
An example of a gene that requires a complex interaction of MANY initiation factors is the _____ gene
Definition
insulin
Term
Some members of this class of junk DNA encode a reverse transcriptase:

Simple sequence repeats (minisatellites)
Alu repeats
Telomeres
Processed pseudogenes
line elements
Definition
line elements
Term
mismatched bases frequently arise from replication errors: t/f?
Definition
t
Term
mismatched bases are removed by glycosidase that creates an AP site? t/f
Definition
f
Term
In humans: all the of the folliwng are transcription activators of RNA pol II except:

HSF
MyoD
p53
Steroid hormone/receptor complexes
TFIIIB
Definition
TFIIIB
Term
Erythromycin targets which subunit of prokaryotic ribosomes?
Definition
50S
Term
The compound Gleevec is useful for treating chronic myelogenous leukemia because it:
Definition
is an inhibitor of the kinase activity of the Bcr-Abl fusion protein
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