Chapter 14
Causes DNA strand separation at the origin of replication
helicase
The three phases of DNA replication are:
initiation, elongation, and termination
Attaches a nucleotide to the 3' end of the DNA strand
polymerase
The major significance of the Hershey Chase experiments is that they
determined that DNA in the genetic material
An Okazaki fragment is a short fragment of DNA created on the ______ strand of DNA
lagging
Synthesized in small fragments that are later connected
lagging strand
Synthesized continuously
leading strand
In cancer cells as compared to normal cells, telomerase is present in ______ levels
lower
The enzyme DNA ________ covalently links nucleotides to synthesize new DNA strands together during DNA replication
polymerase
Differences in prokaryotic and eukaryotic replication
structure of chromosome, number of origins of replication, complexity of enzymology
Griffith performed experiments related to
studying transformation in bacteria
The term ____ refers to the coiling of two DNA strands leading to torsional strain
supercoiling
Steps of lagging strand synthesis
synthesize primers using primase, synthesize DNA, replace RNA primers with DNA, stich fragments together
Why do eukaryotic cells have multiple origins of replication
to ensure timely replication of multiple, relatively large chromosomes
Guanine forms ____ bonds with cytosine
3
A new DNA strand can only be synthesized in a _' to _' direction
5 , 3
In order to purify the genetic material, Avery, MacLeod, and McCarty used what enzymes in their experiments
RNA digesting enzymes, DNA digesting enzymes, and protein digesting enzymes
Not involved in the unwinding of DNA during replication
RNA polymerase
The DNA structure proposed by Watson and Crick involves
a sugar phosphate backbone, helical structure
DNA'S phosphodiester ________ is composed of sugars and phosphates
backbone
The interaction of two strands of DNA via hydrogen bonds is the
double helix
Main eukaryotic DNA polymerases that extend DNA are
epsilon and delta
Chromosomal entities that are an individual's traits
genes
The components of a virus include
genetic material and protein coats
Features of the Watson and Crick model include
helical structure, sugar phosphate backbone, and a double stranded structure
Enzymes involved in DNA replication that are found in all three types of cells (bacteria, archaeal, and eukaryotic)
helicase, primase, polymerases
The primary purpose of the meselson and Stahl experiments was to determine
how DNA replicates
Damage caused by UV light leading to thymine dimers is corrected using ________, which restores the two original bases by cleaving the bond between them
photorepair
Makes a 10-12 bp complementary primer to the DNA
primase
All DNA polymerases require a short strand of DNA or RNA, called a _____ to begin their synthesis
primer
The ______ is part of the replisome composed of primase, helicase, and accessory proteins that prime the lagging strand
primosome
The function of telomeres is to
protect the ends of chromosomes
DIfferent forms of bases, which have to do with keto verses enol and amino verses imino groups are attached to the bases, are called _____
tautomers
Short repeats of DNA on the ends of eukaryotic chromosomes
telomeres
The problems in replicating the ends of the chromosomes deal with
the directionality of polymerases and the need for a primer
Phages are a type of _______ that infect _______ cells. causing them to lyse
viruses, bacteria
Telomeres are related to
cellular aging
Determined x-ray diffraction patterns of DNA structure
Franklin
Showed that there was a transforming principle that could be passed between bacterial cells
Griffith
Determined that DNA was genetic material by studying the T2 bacteriophage
Hershey and Chase
Determined the amount of adenine in DNA always matches thymine and the amount of cytosine always matches guanine
Chargaff
A chromosome is composed of
DNA and proteins
Prepared uniformly oriented DNA fibers
Wilkins
Radiation, UV light, x-rays, and chemicals in the environment are referred to as
mutagens
During semiconservative DNA replication
one of the strands in each new double helix comes from the original molecule, and one is newly synthesized
A ____ of ____ is a site within a chromosome where DNA replication BEGINS
origin, replication
The components of a nucleotide include
phosphate group, sugar, nitrogenous base
DNA backbone is composed of
phosphate groups and sugars
Repeating sugar and phosphate units in a single DNA strand make up the
phosphodiester backbone
The DNA controlled by an origin is called a
replicon
This model of DNA replication suggest one of the strands in each new double helix comes from original molecule, and one is newly synthesized
semiconservative
Target a single kind of lesion in DNA and repair that damage
specific
Determined that DNA was the genetic material by studying the transforming principle
Avery, MacLeod and McCarty
Acts on the lagging strand to remove primers and replace them with DNA
DNA polymerase I
Not involved in replication but used for DNA replication
DNA polymerase II
The main replication enzyme
DNA polymerase III
Facilitates the reversal of damage to our hereditary material before a permanent mutation can occur?
DNA repair systems
Determined a method for the replication of genetic material
Messlson and Stahl
The DNA fibers Franklin used in her x-ray diffraction studies came from
Wilkins
The DNA primase makes
a primer about 10-20 nucleotides in length and a primer of RNA complementary to the DNA
Prokaryotic replication begins at
a single origin
The density of the bacterial DNA following the first round of DNA replication in the Meselson-Stahl experiment can best be described as
an intermediate between 14 N and 15 N
Franklin used x-ray _____ to suggest that DNA has a helical structure
diffraction
This model of DNA replication suggests that newly synthesized strands of DNA have mixtures of parental and newly synthesized strands of DNA:
disperisive
Different models for DNA replication include:
dispersive replication, semiconservative replication, conservative replication
DNA replication in eukaryotic cells is complicated by
linear chromosomes
Repair multiple kinds of lesions in DNA
nonspecific
What 3 items are required for DNA replication?
nucleotides, template, polymerase
The enzyme ______ contains a small internal piece of RNA, which is used to extend the end of a linear DNA molecule
telomerase
______ are short protective repeats of DNA on the ends on eukaryotic chromosomes which are generated by the enzyme ______
telomeres, telomerase
During DNA replication, new strand are synthesized from _____ strands on the original molecule
template
Relieves coiling in DNA strands ahead of the replication fork
topoisomerase
