chapter 14: the genetic material (learnsmart)
A chromosome is composed of
DNA and proteins
3'
OH group
chargaffs rules indicates that the amount of A in a sample is equal to the amount of ____________________ and the amount of C in a sample is equal to the amount of ______________
T,G
What is primase part in dna replication?
makes a 10-2 bp complimentary primer to the DNA
1'
nitrogenous base
components of a nucleotide
nitrogenous base, phosphate, sugar
5'
phosphate group
Repeating sugar and phosphate units in a single DNA strand make up the
phosphodiester backbone
Adjacent nucleotides in the same DNA strand are held together by covalent bonds known as
phosphodiester bonds
The enzyme ____________ can repair uv damage by binding to a thymine dimer and cleaving it, therefore restoring two thymines
photolyase
Telomerase function
prevents chromosome shortening by attaching a repeat sequence to the ends of chromosomes
In the 1950"s, the british researcher maurice wilkins contribute to the discovery of DNA's double helix structure by?
producing uniformly oriented DNA fibers
What is gyrase part in dna replication?
relieves coiling in DNA strands ahead of the replication fork
nonspecific repair mechanism
repair multiple kinds of of lesions in DNA using a single mechanism
DNA replication that leads to the production of double helices with one parental strand and one newly synthesized strand is consistent with ?
semiconservative replication
Telemores
short protective repeats of DNA on the ends of eukaryotic chromosomes
How is the lagging strand synthesized?
synthesized in small fragments that are later connected
specific repair mechanism
target a single kind of lesion in DNA and repair that damage
Griffith's experiments were important because they showed?
that the genetic material could be passed from one cell to another
Replication fork
the partial opening of a dna helix to form two single strands
Franklin determined that the structure of DNA was helical based on?
x-ray diffraction analysis
Different models from dna replication
- semiconservative replication -conservative replication -dispersive replication
The dna structure proposed by watson and crick involve?
-A sugar phosphate background -two grooves (major and minor) - a helical structure
Differences in prokaryotic and eukaryotic replication
-number of origins of replications -complexity of enzymology -structure of chromosome (linear vs circular)
What three items are required for dna replication?
-template -nucleotides -polymerase
three phases of DNA replication
1. Initiation 2. Elongation 3. Termination
excision repair steps
1. Recognition of damage 2.Removal of the damaged region 3. Resynthesis using the information on the undamaged strand as a template
Lagging strand synthesis steps
1.synthesize primers using primers 2.synthesize DNA 3.Replace RNA primers with DNA 4.seals nicks in the DNA
What is a phage?
A type of virus that infects bacterial cells
What is polymerase part in dna replication?
attaches a nucleotide to the 3' end of the dna strand
How is the leading strand synthesized?
continuously
Telomerase
enzyme that generates telomeres
Helicase
enzyme that uses ATP to unwind the DNA template
The enzyme DNA _____________ is the topoisomerase involved in DNA replication
gyrase
DNA replication in eukaryotic cells is complicated by the fact that eukaryotic cells have?
linear chromosomes
