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