genetics final
If tryptophan is amino acid #67 in a particular protein, what is the anticodon of the transfer RNA that delivered tryptophan to this location?
3'-ACC-5'
The polyadenylation signal sequence in eukaryotic mRNA is ______.
5' AAUAAA 3'
On the diagram, which letter represents the 5' and 3' untranslated regions as they appear in the processed transcript?
A
Initiation
A complex forms between the ribosomal subunits, one mRNA molecule and the first tRNA molecule.
What is a spliceosome?
A multicomponent structure that removes introns found in an RNA
What is a promoter?
A specific base-pair sequence that attracts RNA polymerase, either directly or indirectly
The complementarity rule used in transcription is similar to the ______ rule, except that ______ substitutes for thymine in the RNA.
AT/GC; uracil
Which of the following are possible posttranslational modifications?
Addition of a phosphate group Addition of ubiquitin Addition of a carbohydrate
Elongation
Amino acids are linked together in the order designated by the codons.
Which of the following represent common structural features of transfer RNA molecules?
Anticodon sequence Amino acid acceptor stem with a 3' single-stranded region 74-95 nucleotides in length Cloverleaf shape formed by complementary base pairing
Which of the following represent common structural features of transfer RNA molecules?
Anticodon sequence Cloverleaf shape formed by complementary base pairing Amino acid acceptor stem with a 3' single-stranded region 74-95 nucleotides in length
In prokaryotic cells, transcription and translation are coupled, i.e., translation of an mRNA begins _________its transcription has been completed.
BEFORE
Which of the statements correctly describe the energy requirements for transcriptional elongation?
Breaking a bond in a ribonucleotide triphosphate provides the energy needed to form a new bond between two nucleotides.
What are snRNPs?
Components of the spliceosome
The central dogma of genetics can be summed up by which of the following?
DNA → mRNA → polypeptide
Which of the following statements accurately describes the genetic code in different organisms?
In almost all organisms that have been examined by scientists, the same correspondence between codons and amino acids is found.
How does a hairpin loop form during termination of transcription in bacteria?
It forms within the mRNA through complementary pairing of nucleotides in the same molecule.
When a polypeptide is synthesized, the first amino acid to be put in place is located at the
N terminus
Addition of a phosphate group to a polypeptide is a
POSTTRANSLATIONAL MODIFICATION
Addition of a phosphate group to a polypeptide is a
POSTTRANSLATIONAL modification
Transcription is the process of synthesizing
RNA from a DNA template
A ribozyme is a(n) ____.
RNA molecule with catalytic activity
Which enzyme synthesizes RNA during transcription?
RNA polymerase
Which RNA polymerase transcribes genes that encode proteins in eukaryotes?
RNA polymerase II
Which components are assembled into the subunits of a ribosome?
Ribosomal proteins Ribosomal RNA
RNA splicing requires the aid of a multicomponent structure called the
SPLICESOME
Which of the following are functions of the 5' cap of eukaryotic mRNAs?
Stabilizes the mRNA in the cytoplasm Recognition of the transcript by translation initiation factors
Termination
The newly produced polypeptide is released from the ribosome.
A mutation in the E. coli tryptophan synthase gene produces glutamic acid (Glu) instead of glycine (Gly) at position 211 of the protein and the bacteria are unable to survive in the absence of tryptophan. A different mutation produces valine (Val) at the same position and the bacteria can survive in the absence of tryptophan. What is the conclusion from this result?
The tryptophan synthase enzyme can function with either Gly or Val at position 211.
Transcription occurs in how many stages?
Three stages: initiation, elongation, and termination
Which of the following nucleotides are used during transcription?
UTP and ATP CTP and GTP
A polyribosome is
a messenger RNA transcript that has many bound ribosomes in the act of translation
A polyribosome is ______.
a messenger RNA transcript that has many bound ribosomes in the act of translation
The capping of a eukaryotic mRNA is an event that involves the addition of
a methylated guanosine in reverse orientation.
The modification that occurs at the 3' end of eukaryotic mRNAs is known as _____.
a poly-A tail
The universality of the genetic code means that
all organisms have a common ancestor mouse mRNA can be translated by ribosomes from frog egg cytoplasm
When a polypeptide is synthesized, the first amino acid to be put in place is located at the ______.
amino- or N-terminus
Enzymes known as aminoacyl-tRNA synthetase , are responsible for attaching amino acids to their corresponding tRNAs.
aminoacyl synthetase
To bring a specific amino acid into its location on a polypeptide chain, which sequence on transfer RNA must bind to messenger RNA?
anti cordon
The order in which amino acids are added to a polypeptide chain is determined by hydrogen bonding between each codon and the ______ of the tRNA carrying the amino acid.
anticardon
During elongation, the ______ of the incoming tRNA binds to the ______ of the mRNA
anticodon; codon
During elongation, the ______ of the incoming tRNA binds to the ______ of the mRNA.
anticodon; codon
The 5' and 3' untranslated regions of a mature eukaryotic mRNA ____.
are located within exons facilitate efficient translation
The function of an aminoacyl-tRNA synthetase enzyme is to catalyze the
attachment of an amino acid to its appropriate tRNA
A loss-of-function mutation _____.
can occur outside the coding region can reduce the amount of functional protein can occur within the coding region
The addition of a methylated "backward G" to the 5' end of a eukaryotic mRNA is a process known as ______.
capping
The flow of genetic information in a cell, from DNA to RNA to protein, is described as the I genetics.
central dogma
The flow of genetic information in a cell, from DNA to RNA to protein, is described as the
central dogma of genetics
A series of three nucleotide bases that specifies a particular amino acid is a
codon
Which of the following is not a feature of transfer RNA molecules?
codon
What do scientists mean when they say that a gene's DNA sequence is colinear with the amino acid sequence of the encoded polypeptide?
colinear
During DNA replication, DNA polymerase forms phosphodiester bonds between ______ triphosphates, whereas during transcription, RNA polymerase forms bonds between ______ triphosphates.
deoxyribonucleotide; ribonucleotide
About 250 adenine nucleotides, called a ____________, are enzymatically added to a eukaryotic mRNA after it is transcribed.
during the initiation phase of transcription
A eukaryotic promoter differs from a prokaryotic promoter because _____.
eukaryotic promoters are bound by histone proteins that must be released
Regions of DNA that are represented in a mature transcript are
exons
Sequences known as exons are _____.
expressed regions of DNA that are present in a mature mRNA
A mutation that increases the activity of a protein is a _____.
gain-of-function allele
Which amino acid will be carried by a tRNA with the following anticodon: 3'-GUG-5'?
histodine
In bacteria, the term open promoter complex refers to the small bubble-like structure that forms
initialization
The three stages of transcription are called
initiation, elongation, and termination
Sequences of DNA that are not represented in the mature mRNA are called ____.
introns
are intervening sequences of DNA that are not represented in mature mRNA.
introns
A mutation in the location indicated by the thick blue arrow in the diagram
may alter the amount of protein produced by the gene.
A base substitution in DNA that ultimately leads to a change in the encoded amino acid is called a(n)
missense
A snRNP consists of small uridylic acid-uridylic acid-rich , and proteins.
nuclear rna
A nucleotide triplet, called a codon, specifies
one amino acid
A nucleotide triplet, called a codon, specifies ______.
one amino acid
About 250 adenine nucleotides, called a _______ are enzymatically added to a eukaryotic mRNA after it
poly-A or poly a
A single mRNA that contains the coding information for several distinct polypeptides is
polycistronic
The enzyme that synthesizes RNA from a DNA template is called
polymerase RNA
In ______ cells, the initiator tRNA carries the amino acid N-formylmethionine.
prokaryotic
The complex of RNA polymerase holoenzyme bound to an unwound template strand of DNA during the initiation phase of transcription is called the
promoter open
The sequence in DNA that signals RNA polymerase where to begin transcription is called the
promoter or promoters
Each ribosomal subunit is assembled from ribosomal RNA and many different
protein
Noncoding genes include those for
rRNAs snRNAs tRNAs
A coding region on a single DNA strand can be read in three different ways, depending on the position of the first codon. Thus, the first codon determines the region's
reading frame
During termination of translation in bacteria, a stop codon is recognized by a(n)
release factor
The component that recognizes a stop codon during termination of translation in bacteria is ______.
release factor
In prokaryotes, the transcription terminator is a
sequence in the transcript that specifies the end of transcription
The process that removes introns from a primary transcript and joins together successive exons is called RNA
splicing
An AUG codon, which specifies the amino acid methionine and is often the first codon that begins a polypeptide sequence, is called the
start codon
In prokaryotic cells, a transfer RNA carrying N-formylmethionine recognizes the ______ and is the first tRNA to bind to the ribosomal subunits, so it is called the initiator tRNA.
start codon
The series of three nucleotide bases that specifies the placement of the amino acid methionine at the beginning of a polypeptide chain is the _____.
start codon
The sequence in DNA that signals the end of transcription is known as the
terminator
While working on deciphering the genetic code, Crick and Benner hypothesized that each gene has a single starting point which establishes
the reading frame
RNA splicing refers to
the removal of introns from RNA
The poly-A tail added to eukaryotic transcripts serves
to enhance the efficiency of translation
The poly-A tail added to eukaryotic transcripts serves _____.
to increase the stability of the mRNA in the cytoplasm to enhance the efficiency of translation
The synthesis of an RNA molecule from a DNA template is called
transcription
Which type of RNA is shown in the figure?
transfer rna
The synthesis of a polypeptide molecule from an mRNA template is called
translation
In prokaryotic cells, the coupling of transcription and translation refers to ______.
translation of an mRNA beginning before its transcription has been completed.
The structure shown in the figure is a hairpin loop that forms _______.
within an mRNA during transcription termination as a result of complementary bases within an mRNA when RNA polymerase is being released from DNA