ch14
leading strand lagging strand
synthesized continuously synthesized in small fragments that are later connected
specific nonspecific
target a single kind of lesion in DNA and repair that damage repair multiple kinds of lesions in DNA, using a single mechanism
Griffith performed experiments, which demonstrated
transformation in bacteria
Franklin determined that the structure of DNA was helical based on
x-ray diffraction analysis
What type of repair mechanism is responsible for removing bases that were incorrectly inserted into DNA during replication?
Mismatch repair
What is the name of the subunit that acts as the sliding clamp, which keeps the replicating enzyme complex attached to the template in eukaryotic cells.
PCNA
Polymerase
attaches a nucleotide to the 3' end of the DNA strand
DNA's phosphodiester _____ is composed of sugars and phosphates.
backbone
The two main eukaryotic DNA polymerases that extend DNA are
epsilon delta
The enzyme ____ uses ATP to unwind the DNA template.
helicase
The enzyme _____ uses ATP to unwind the DNA template.
helicase
DNA replication in eukaryotic cells is complicated by the fact that eukaryotic cells have
linear chromosome
____ repair is responsible for removing bases that were incorrectly incorporated into DNA during replication.
Mismatch
What is the name of the regions at the ends of eukaryotic chromosomes?
Telomeres
Which of the following are short repeats of DNA on the ends of eukaryotic chromosomes?
Telomeres
Choose all characteristics of the transforming substance isolated by Avery, MacLeod and McCarty.
The elemental composition of the substance was very similar to that of DNA.--- RNA-digesting enzymes did not affect its transforming ability.----- Protein-digesting enzymes did not affect its transforming ability.------ DNA-digesting enzymes destroyed its transforming ability.
An ______ cuts DNA internally and an ______ cuts at the ends of DNA.
endonuclease; exonuclease
Based on replication proteins, DNA replication in archaea is most similar to that of
eukaryotes
This type of primase is a combination of RNA polymerase and DNA polymerase that makes short RNA primers and then extends them with DNA to produce the final primer:
eukaryotic
E. coli polymerases I, II, and III have 3' to 5' ______ activity, which provides them with a proofreading function, i.e. they can remove a mispaired base.
exonuclease
Radiation, UV light, x-rays, and chemicals in the environment can cause mutations in DNA and are therefore referred to as
mutagens
Of the following list, which 3 items are required for DNA replication
nucleotides polymerase template
Select all of the following that are components of a nucleotide.
sugar phosphate group nitrogenous base
The DNA backbone is composed of (choose all that apply)
sugars. phosphate groups.
Short, repeated sequences of DNA are characteristic of
telomeres
Griffith's experiments were important because they showed
that the genetic material could be passed from one cell to another
primase
makes a 10-12 bp complementary primer to the DNA
Agents that cause mutation are known as
mutagens
Which types of cells have more than one origin of replication?
Eukaryotes
In which of the following chromosomal entities are an individual's traits specified?
Genes
Which of these is not required for DNA replication?
NADPH
The function of telomeres is to
protect the ends of chromosomes
Which enzymes did Avery, MacLeod, and McCarty use in order to identify the genetic material?
DNA digesting enzymes RNA digesting enzymes protein digesting enzymes
The enzyme that relieves DNA supercoiling ahead of the replication fork is
DNA gyrase
Which of the following facilitates the reversal of damage to our hereditary material before a permanent mutation can occur?
DNA repair systems
In their experiments, Avery, MacLeod, and McCarty isolated a substance, which had a transforming activity. Which of the following destroyed that substance's ability to transform bacterial cells?
DNA-digesting enzymes
Which of the following enzymes involved in DNA replication are found at the replication fork in all three types of cells (bacterial, archaeal, and eukaryotic)? Choose all that apply.
Helicase Clamp loader Polymerases Sliding clamp Primase
The experiments with radioactively labeled phage that showed that DNA was the genetic material were performed by
Hershey and Chase
Why do eukaryotic cells have multiple origins of replication?
To ensure timely replication of multiple, relatively large chromosomes
Features of the Watson and Crick model include
a helical structure; a sugar phosphate backbone; a double stranded structure
Bacterial replication (for example in E. coli) begins at
a single origin
The DNA structure proposed by Watson and Crick involves
a sugar phosphate backbone two grooves (major and minor) a helical structure
Nucleotides contain a sugar, a phosphate, and a nitrogenous
base
Genes, which contain trait specifying information, are located on
chromosomes
The major significance of the Hershey and Chase's experiments is that they
determined that DNA is the genetic material
Franklin used x-ray ___ to suggest that DNA has a helical structure.
diffraction/crystallography
During DNA replication, the ________ strand is synthesized continuously while the ______ strand is synthesized as small fragments that are connected to each other to form a continuous strand.
leading, lagging
During semiconservative DNA replication
one of the strands in each new double helix comes from the original molecule, and one is newly synthesized.
Repeating sugar and phosphate units in a single DNA strand make up the
phosphodiester backbone.
In the replisome, the ___ is composed of primase, helicase, and accessory proteins that prime the lagging strand.
primosome
In the replisome, the____ is composed of primase, helicase, and accessory proteins that prime the lagging strand.
primosome
The results of the Hershey and Chase experiments suggested that DNA was the genetic material because
radioactive bacteriophage DNA was found in the cytoplasm of bacterial cells
gyrase
relieves coiling in DNA strands ahead of the replication fork
The DNA controlled by an origin is called a
replicon
DNA replication that leads to the production of double helices with one parental strand and one newly synthesized strand is consistent with
semiconservative replication
When the double stranded DNA helix is unwound, two single strands of DNA are formed. These strands have to be stabilized because their hydrophobic bases are exposed to water. The proteins that stabilize the two single strands are called
single-strand binding proteins
The two general categories of DNA repair are
specific nonspecific
List several differences in prokaryotic and eukaryotic replication.
structure of chromosome (linear vs. circular) complexity of enzymology number of origins of replication
The enzymes in the replisome are active on
the leading and the lagging strands
DNA repair mechanisms have likely evolved because
there is no way for cells to avoid exposure to mutagens
Helicase
unwinds the double helix