chapter 13 & 14
in which image will adenine be the next nucleotide to be added to the primer
(left to right) T,G, C, G, A
In a nucleotide, the nitrogenous base is attached to the sugar's _____ carbon and the phosphate group is attached to the sugar's _____ carbon.
1' ... 5' The nitrogenous base is attached to the sugar's 1' carbon and the phosphate group is attached to the sugar's 5' carbon.
A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be
3' AAA-GAA-TAA-CAA 5'
A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is
3' UCA 5'
RNA polymerase moves in which direction along the DNA
3' to 5' along the template strand
nucleic acids are assembled in the ____ direction
5' to 3'
the direction of synthesis of a RNA transcript is
5' to 3'
What is the %T in wheat DNA?
Approximately 28%
which of these is tRNA
B
a nitrogenous base is indicated by the letter
C
Which of these is(are) pyrimidines?
C, D, E
The tRNA anticodon, GAC, is complementary to the mRNA codon with the sequence
CUG
in the diagram below the two blue strands represent
DNA
which of these is a difference between a DNA and an RNA molecule
DNA is usually double-stranded, whereas RNA is usually single-stranded.
the enzyme that can replicate DNA is called
DNA polymerase
during DNA replication, which of the following enzymes removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of the okazaki fragments?
DNA polymerase 1
DNA replication is said to be semi conservative. What does this mean
Each new double helix consists of one old and one new strand.
Which of these correctly illustrates the pairing of DNA and RNA nucleotides?
GTTACG CAAUGC
sort the phrases into the appropriate bins depending on which protein they describe
Helicase: breaks H-bonds between bases, binds at the replication fork Ropoisomerase- binds ahead of the replication fork, breaks covalent bonds in DNA backbone Single strand binding protein- binds after the replication fork, prevents H-bonds between bases
which of the following statements correctly describes alternative RNA splicing?
It can allow the production of proteins of different sizes and functions from a single mRNA.
which of the following is a function of a poly-A tail in mRNA?
It helps protect the mRNA from degradation by hydrolytic enzymes.
What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?
It joins Okazaki fragments together.
Where does RNA polymerase begin transcribing a gene into mRNA?
It starts after a certain nucleotide sequence called a promoter.
what is the function of helicase in DNA replication?
It untwists the double helix and separates the two DNA strands.
what is the function of RNA polymerase
It unwinds the double helix and adds nucleotides to a growing strand of RNA.
____________ are the short sections of DNA that are synthesized on the lagging strand of the replicating DNA.
Okazaki fragments
the initiator tRNA attaches at the ribosomes ____ site.
P
in the diagram below the gray unit represents
RNA polymerase
which of the following statements best describes the termination of transcription in prokaryotes?
RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript
The synthesis of a new strand begins with the synthesis of a(n) _____.
RNA primer complementary to a preexisting DNA strand
Who conducted the X-ray diffraction studies that were key to the discovery of the structure of DNA?
Rosalind Franklin
what is meant by translocation
The ribosome slides one codon down the mRNA.
Which of these nitrogenous bases is found in DNA but not in RNA?
Thymine
Does the distribution of bases in sea urchin DNA and salmon DNA follow Chargaff's rules?
Yes, because the %A approximately equals the %T and the %G approximately equals the %C in both species.
During RNA processing a(n) _____ is added to the 5' end of the RNA.
a long string of adenine nucleotides
Polypeptides are assembled from _____.
amino acids
Translation occurs in the _____.
cytoplasm
After replication is complete, the new DNAs, called _____, are identical to each other.
daughter DNA
After DNA replication is completed, _____.
each new DNA double helix consists of one old DNA strand and one new DNA strand
which of the following types of mutations could result in a frameshift mutation
either an insertion or a deletion of a base
The RNA segments joined to one another by spliceosomes are _____.
exons
The flow of information in a cell proceeds in what sequence?
from DNA to RNA to protein
____ of translation always happens at the start codon of the mRNA
initiation
what is the name of the process shown in the diagram
initiation of translation
After an RNA molecule is transcribed from a eukaryotic gene, what are removed and what are spliced together to produce an mRNA molecule with a continuous coding sequence?
introns ... exons Introns, intervening sequences, are removed and the exons, expressed sequences, are spliced together
The new DNA strand that grows continuously in the 5' to 3' direction is called the _____.
leading strand
RNA processing converts the RNA transcript into _____.
mRNA
Examine the table of codons in Figure 14.2. What amino acid sequence will be produced based on the following mRNA codon sequence? 5'-AUG-UCU-UCG-UUA-UCC-UUG-3'
met-ser-ser-leu-ser-leu
During RNA processing a(n) _____ is added to the 5' end of the RNA.
modified guanine nucleotide
This is an image of a(n) _____.
nucleotide
the letter A indicates a
phosphate group
which of the following enzymes synthesizes short segments of RNA?
primase
in the diagram below the green unit represents
promoter
what is the function of topoisomerase?
relieving strain in the DNA ahead of the replication fork
During DNA replication, an open section of DNA in which a DNA polymerase can replicate DNA, is called a
replication fork
The action of helicase creates _____.
replication forks and replication bubbles
Where does translation take place?
ribosome
which of the following help(s) to hold the DNA strands apart while they are being replicated?
single strand binding proteins
_____ of translation happens when the ribosome hits a stop codon on the mRNA.
termination
A codon consists of _____ bases and specifies which _____ will be inserted into the polypeptide chain.
three ... amino acid
In a DNA double helix an adenine of one strand always pairs with a(n) ____ of the complementary strand, and a guanine of one strand always pairs with a(n) ____ of the complementary strand
thymine ... cytosine
In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the complementary strand, and a guanine of one strand always pairs with a(n) _____ of the complementary strand.
thymine and cytosine
the process, performed by the ribosome, of reading mRNA and synthesizing a protein is called
translation
Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine?
8%
In an analysis of the nucleotide composition of DNA, which of the following will be found?
A + C = G + T
At which site do new aminoacyl tRNAs enter the ribosome during elongation?
A-site This is the site at which new aminoacyl tRNAs that are complementary to the mRNA codon enter the ribosome.
the diagram below shows a bacterial replication form and it's principal proteins
A.) breaks hydrogen bonds, unwinding DNA double helix, B.) synthesizes RNA primers on leading and lagging strands, C.) replaces RNA primers with DNA nucleotides D.) catalyzes phosphodiester bond formation, joining DNA fragments E.) lagging strand G.) relaxes supercoiled DNA H.) coats single stranded DNA I.) synthesizes DNA 5' to 3' on leading and lagging strands F.) leading strand
which one of the following is true of tRNAs
Each tRNA binds a particular amino acid.
in DNA from any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine. Which of the following investigators was (were) responsible for this discovery?
Erwin Chargaff
True or false. A tRNA with an anticodon complementary to the stop codon catalyzes the reaction by which translation is terminated.
False There are no tRNAs complementary to the three stop codons; termination occurs when release factors recognize the stop codon in the A-site and catalyze the release of the polypeptide from the tRNA in the P-site.
what name is given to the process in which pre-mRNA is edited into mRNA
RNA processing
what is meant by the description "antiparallel" regarding the two strands of nucleic acids that make up DNA?
The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand
the chemical structure of DNA and its nucleotides
a.) 5' end b.) hydrogen bond c.) 3' end d.) deoxyribose sugar e.) nitrogenous base f.) phosphate group g.) 3' end h.) 5' end
Drag the arrows onto the diagram below to indicate the direction of the DNA polymerase 3 moves along the parental (template)
a.) ➡️ b.) ➡️ c.) ⬅️ d.) ⬅️
What enzyme catalyzes the attachment of an amino acid to tRNA
aminoacyl-tRNA synthetase
amino acids are attached to tRNA by enzymes called
aminoacyl-tRNA synthetase
during DNA replication, which of the following enzymes separates the DNA strands during replication?
helicase
Which nucleic acid is translated to make a protein?
mRNA
the RNA that has an amino acid attached to it, and that binds to the codon on the mRNA, is called a
tRNA
What are the repetitive DNA sequences present at the ends of eukaryotic chromosomes called?
telomeres
An old DNA strand is used as a _____ for the assembly of a new DNA strand.
template
what name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA
transcription
what name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?
translation
Which enzyme catalyzes the elongation of a DNA strand in the 5' to 3' direction?
DNA polymerase III
Why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments?
DNA polymerase can assemble DNA only in the 5' to 3' direction
In the accompanying image, a nucleotide is indicated by the letter _____.
B