Test 3: Fill in the Blanks Flashcards
During initiation of translation, the initiator tRNA associates after the ___________ has been bound to the small subunit.
mRNA transcript
Intact ribosomes must be dissociated by _____ in order for _________ to occur.
IF-3, initiation
Gene families appear to be built by cycles of ________ followed by ___________.
duplication, mutation
All members of a gene family will share a high degree of sequence homology, even the unexpressed ___________.
pseudogenes
The predominant form of guanine in DNA is the ____, but it can undergo _____________ to produce the ____ form.
keto, tautomerization, enol
In eukaryotic genes, there are often many non-coding regions called ______, interspersed between the coding _____ sequences.
introns, exons
Post transcriptionally all eukaryotic mRNAs receive a _______, but only some also receive a __________.
5’ cap, poly-A tail
Primary damage of DNA caused by exposure to ultraviolet light is ___________ of bases.
dimerization
The most common cause of spontaneous mutations is _____________.
tautomerization
Associated with eukaryotic chromatin are octamers if ________ proteins that ultimately are involved in the formation of ____________.
histone, nucleosomes
Very high levels of DNA damage can lead to the activation of the ____ response.
SOS
During Interphase, most eukaryotic chromatin is organized either at the ______________ or the _______________.
nucleosome (100 Angstrom), solenoid (300 Angstrom) level
During translation, each new charged tRNA is brought into the A site with the assistance of ______.
EF-Tu
Ribosomes serve as the __________ workbench for translation.
non-specific
Transcriptional units with two or more separate coding sequences are called _____________.
polycistronic
The main damage caused by UV exposure is the formation of ________, and the two categories of repair processes that exist are ___________ and ______________.
dimers, light dependent, light independent
Effector molecules in regulation can either be ______ or _______, depending on the effect they have on ________________ activity.
positive, negative, regulatory transcriptional
If a purine is substituted for a pyrimidine, a __________ mutation has occurred.
transversion
Hydrophobic mutagens that interact physically with DNA molecules are called _________ agents, and are particularly harmful because they may cause ___________ mutations.
intercalating, frameshift
A unique feature of bacterial genome function is that ____________ and ____________ can occur simultaneously.
transcription, translation
Exposure to nitrous acid leads to __________________ and adenine will become ___________.
oxidative deamination, hypoxanthine
All tRNA molecules will have at least 4 ______________ regions formed by _____________.
double stranded, inverted repeats
Point mutations are the result of ____________ of one base for another in a DNA sequence.
substitution
In an inducible system the _________ of the regulated pathway is involved in transcribing the required genes.
promoter
Class I eukaryotic genes are most like ________ genes because the transcripts are ___________.
bacterial, short/primitive
The repressor proteins of both inducible and repressible systems are produced ___________, but only that of ________ operons, by ______ binds to the promoter.
continuously, inducible, itself
In a re-association kinetics study, the A260 will _________ as more DNA becomes ___________.
decrease, re-associated
Movement of DNA within a genome, often with mutagenic consequences, is the result of ____________.
transposons
The basic unit of organization in eukaryotic chromatin is the __________, which consists of an octamer of 4 histone proteins associated with ______________ of DNA, combined with __________.
nucleosome, 146 base pairs, linker DNA
The activation of the SOS response is caused by the action of the protein ______.
Rec A
After termination of translation, ____ binds the ribosome and causes dissociation of the subunits, and then also aids in the binding of the ______ to the small sub-unit in the next initiation event.
IF3, mRNA
Most inducible operons are associated with _______ pathways.
catabolic
In classifying mutations on the basis of ultimate causes, they can be either __________ or ________.
spontaneous, induced
The -imino form of cytosine is complementary to _________.
adenine
Induction of the lac operon occurs when _______ interacts with the repressor protein.
lactose
Additions or deletions of nucleotides into a DNA sequence can cause __________ mutations.
frameshift
Simultaneous transcription and translation allows for the ____________ of repressible operons.
attenuation
Two general types of causative agents for induced mutations are __________ and ____________.
chemicals, UV radiation
Digesting the ends of nucleic acids can be accomplished with ____________.
exonucleases
The repressor protein in a repressible operon binds to the DNA only when first bound by the ___________, which causes the __________ of transcription.
co-repressor, inhibition
In a transversion mutation, ________ is substituted for a _________.
purine, pyrimidine
In initiation of translation, ____ aids in the binding of mRNA with the small ribosomal sub-unit and ___ aids in the binding of the initiator tRNA.
IF3, IF2
The most important types of mutation from the long term perspective of populations are _________.
germinal
Of the histones, ___ occurs in half the concentration of the other ____ proteins.
one, four
Addition of the 5’ cap to mRNA is catalyzed by the enzyme _______________ and involves the addition of guanine by a _________ bond.
guaninyl transferase, phosphate
The initial discovery of middle repetitive DNA came from studies of __________________.
Reassociation Kinetics
In eukaryotic gene organization, the nucleosome is a unit composed of an octamer of histones that associates with ___.
DNA
In order for the lac operon to be expressed, ________ must be present to remove the repressor protein and enough _______ must have formed to bind and promote transcription.
lactose, cAMP
A higher T-melt temperature is seen with ___ rich DNA.
G-C
Permanent inactivation of genes such as is seen in Barr bodies formed from X chromosomes involves packaging of DNA into ______________.
looped domains
The _____ form of thymine is complementary with adenine but the ______ form complements guanine.
keto, enol
The ability of bacteria exposed to UV to recover in the dark was evidence of ___________ repair and this was confirmed by the presence of tritiated _____ in the buffer.
base excision, H3-T
Because so much of DNA is non-coding in eukaryotes, the ___________ is much lower than that of prokaryotic genomes.
gene density
Directionality of translation in prokaryotes is established by __________ because the _________ of the amino acid has been chemically altered to methionine.
initiator tRNA, N-terminus
By the end of condensation, there is a _______ fold reduction in length of the genetic material.
10,000
The final gene that codes for immunoglobin includes components from both the ________ and _______ gene libraries.
constant, variable
Two types of post-transcriptional processing in eukaryotes that help slow the degradation of mRNAs are _____ and _________.
5’ cap, poly-A tail
Removal of non-coding regions from a primary transcript can be ____________ or by way of the ____________.
autocatalytic, spliceosome
Two general types of substitutional mutations are __________ and ___________.
transitions, transversions
Excessive DNA damage that leads to high amounts of single-strandedness tends to activate the ___ system, and repair that occurs will be ______________.
SOS, highly erroneous
A large ribosomal sub-unit in eukaryotes consists of _______ separate RNA molecules.
three
In bacterial gene expression, it is not uncommon for ___________, _____________, and __________ to occur simultaneously.
transcription, translation, and degradation
Deamination of adenine produces the base ___________, which is complementary to __________.
hypoxanthine, cytosine
The “cut and paste” repair method for dimers encountered during replication is called __________________, but the dimer is not _________.
recombinational repair, removed
The consequence of exposure to nitrous acid is oxidative deamination, and can lead to ___________.
point mutations
The first step in activating the lac operon involves the removal of the ___________ by the binding of ________.
I-protein, lactose
One bad thing about alkylating agents is they can lead to the activation of ___ repair.
SOS
The basic level of chromatin organization involves _____ wrapped around the __________.
DNA, platysome
In an attenuated operon (tryp), the rate of successful transcription will increase if the amino acid concentration is ____ because translation of the leader polypeptide will _____.
low, stall
Class III genes are transcribed by RNA polymerase III and include genes coding for ______, _______, and __________.
tRNA, snRNA, and 5S rRNA.
The eukaryotic equivalent of the prokaryotic Pribnow is the __________.
TATA box
The _________ represents the sum total of all transcriptional activity in a given nucleus.
HnRNA
An antibody is coded for by a gene, which is custom built with sequences taken from the ________ and ________ libraries.
constant. variable
Alternative spicing options lead to the formation of _________ products.
isoform
Exposure to nitrous acid causes ____________, and cytosine becomes complementary to ________.
point mutations, adenine
On average, DNA is a double stranded molecule, but _______ leads to the equilibrium occurrence of single stranded regions.
breathing
During translocation of translation, the energy of _____ is utilized by the ribosome as it moves _______ down the message.
GTP, 1 codon
A ribosomal sub-unit is composed of _______ and a set of ________.
rRNA, proteins
If oxidative deamination of cytosine occurs, the product is _______, which is complementary to _________.
uracil, adenine
Translocation of the ribosome is aided by the accessory protein ______.
EF-G
Enzymatic activity in the ribosome by _____________ leads to the linking of amino acids.
peptidyl transferase
