Biology 2 Exam 4 Part 1
eukatyotic transcription
-transcription and RNA processing in cell -translation outside of cell -mRNA must be process before translation can occur
missense mutation
A base-pair substitution that results in a codon that codes for a different amino acid.
spliceosome
A large complex made up of proteins and RNA molecules that splices RNA by interacting with the ends of an RNA intron, releasing the intron and joining the two adjacent exons.
nonsense mutation
A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein.
TATA box
A promoter DNA sequence crucial in forming the transcription initiation complex.
transcription factors
A regulatory protein that binds to DNA and affects transcription of specific genes.
signal peptide
A stretch of amino acids on a polypeptide that targets the protein to a specific destination in a eukaryotic cell.
tRNA binding sites
A: attach, P: peptide bond; E: exit
nucleic acid hybridization
Base pairing between a gene and a complementary sequence on another nucleic acid molecule.
artificial selection
Breeding organisms with specific traits in order to produce offspring with identical traits.
exons
Coding segments of eukaryotic DNA.
What is not directly involved in translation?
DNA
what correctly define the most correct and complete description of a gene
DNA sequence that is expressed to form a functional product (RNA or protein)
DNA to Proteins
DNA-transcription-RNA-translation-protein
DNA polymerase
Enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule
directional selection
Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve
poly-A tail
Modified end of the 3' end of an mRNA molecule consisting of the addition of some 50 to 250 adenine nucleotides.
stabilizing selection
Natural selection that favors intermediate variants by acting against extreme phenotypes
Introns
Noncoding segments of nucleic acid that lie between coding sequences.
RNA splicing
Process by which the introns are removed from RNA transcripts and the remaining exons are joined together.
genetic engineering
Process of making changes in the DNA code of living organisms
Ribozymes
RNA molecules that function as enzymes
RNAP
RNA polymerase
transcription initiation
RNA polymerase identifies where to begin transcription
transcription Elongation
RNA polymerase moves along DNA and untwists the double helix as RNA nucleotides are added to the chain
transcription termination
RNA polymerase stops transcription when it encounters terminator in the DNA sequence
sticky ends
Single stranded ends of DNA left after cutting with enzymes
transcription initiation complex
The completed assembly of transcription factors and RNA polymerase bound to a promoter.
gene cloning
The production of multiple copies of a gene.
a triplet of bases in the coding sequence of DNA is AAA. The anti codon on the tRNA that binds the mRNA codon is
UUU
which types of mutation, resulting in an error in the mRNA just after the 5' AUG start codon will have the biggest effect
a deletion of 2 nucleotide
Frame shift
a genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read
silent mutation
a mutation that is neither harmful nor beneficial (found on the end of codon at the 3rd base point or in non coding region)
variation
all new alleles are the result of nucleotide variability
polymerase chain reaction (PCR)
allows the amplification of a small DNA fragment using primers that flank the region
point mutations
alter a single base
Hardy-Weinberg equation
an assessment of evolution at a particular locus
restriction endonucleases
an enzyme that cuts DNA at specific sites, producing small fragments
P site
binds the tRNA attached to the growing peptide chain
A site
binds the tRNA carrying the next amino acid
signal recognition particle (SRP)
binds to signal peptide and escorts the signal peptide and its ribosome to the receptor in the ER membrane
accuracy in the the translation of mRNA into the sequence of amino acids depends on the specific in which of the following
bonding of the anticodon to the codon and the attachment of amino acids to the chain
evolution of a gene
can happen whenever any of the conditions for HWE are not met for that gene
Mutations
changes in the genetic material of a cell
recombinant DNA
combined plasmid and DNA from a different source "foreign DNA"
the anticodon of a particular tRNA molecule is
complementary to the corresponding mRNA codon
pre-mRNA
contains introns, exons. 5' cap and 3' poly-A tail
DNA ligase
enzyme that chemically links DNA fragments together
disruptive selection
form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle
peptide transferase
forms peptide bonds carried out by ribosomal RNA (rRNA)
Single base insertion or deletion
frameshift
genetic drift
in evolution which driving factor most consistently requires a small population as a precondition for its occurrence
result of adaptive evolution
increase in frequency of alleles that provide reproductive advantage
population biology
individual of the same species that live in the same species and can interbreed
Transcription steps
initiation, elongation, termination
Translation steps
initiation, elongation, termination
Indels
insertions or deletions of a few base pairs
what correctly describes the function of a signal peptide
it assists in the translation of polypeptides across the ER membrane
which is the function of the release factor in translation
it binds to the stop codon in the A site in place of a tRNA
function of release factor in translation
it binds to the stop codon in the A site of tRNA
what is the effect of a nucleotide pair substitution that results in a nonsense mutation in a gene
it introduces a premature stop codon into the mRNA
what happens to the cut out intro after alternative RNA splicing
it is rapidly degraded
best summarizes evolution as it is view today
it is the differential survival and reproduction of the most-fit phenotypes
in what way could a point mutation in DNA make a difference in the function of a protein
it might substitute a different amino acid, which could change its function
translation initiation
mRNA, tRNA, and the ribosomal subunits form a complex
mRNA
messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome
genetic varitation
must be present in a pop before natural selection can act upon the pop
natural selection
mutations occur at random and can preserve and distribute beneficial mutations
coding stand
non template stand
beadle and Tatum
one gene one enzyme
gene flow
over time the movement of people of earth had increase. this alter the course of human evolution
cloning vector
plasmids that carry the cloned DNA
RNA polymerase
pries the DNA strands apart and joins together the complementary RNA nucleotides. assembles polynucleotides in the 5' to 3' direction. Can start without primer unlike DNA polymerase
ribosomes
protein building machines and are composed of many proteins and RNA
sickle cell anemia
result of a single missense mutation
rRNA
ribosomal RNA; type of RNA that makes up part of the ribosome
translation termination
ribosome encounter a stop a codon and releases polypeptide
There are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. This is best explained by the fact that
rules for base pairing between the 3rd base of a codon and tRNA are flexible
what must happed to a newly made polypeptide before it can be secreted from a cell
signal sequence must target it to the ER after which it goes to the Golgi app
start codon (AUG)
signifies the start of the protein-encoding sequence in mRNA
Plasmids
small circular DNA molecules that replicate separately from the bacterial chromosome
most likely to produce an African butterfly species in the wild whose members have one pattern
stabilizing selection
Transcription
synthesis of an RNA molecule from a DNA template
translation elongation
tRNAs bring amino acids to the ribosome for incorporation into the polypeptide
Pribnow box
the TATAAT sequence that is often found at the -10 region of bacterial promoters
E site
the exit site, where discharged tRNAs leave the ribosome
gene expression
the process by which DNA directs protein synthesis, includes two stages: transcription and translation
Tranlation
the synthesis of a polypeptide using the genetic information encoded in an mRNA molecule
Prokaryotic Transcription
transcription and translation occur in all in the cell at the same time
tRNA
transfer RNA; type of RNA that carries amino acids to the ribosome
