Chapter
Objectives
- Explain why researchers
originally thought protein was the genetic material
- Summarize the experiments
performed by the following scientists
- Frederick Griffith
- Alfred Hershey and
Martha Chase
- Erwin Chargaff
- Avery, McCarty,
and MacLeod
- List the 3 components
of a nucleotide
- Distinguish between
ribose and deoxyribose
- List the nitrogen bases
found in DNA and distinguish between pryrimidine and purine
- Explain how Watson and
Crick deduced the structure of DNA and describe what evidence
they used
- Explain the base-pairing
rule and describe its significance
- Describe the structure
of DNA and explain what kind of chemical bond connects the
nucleotides of each strand and what type of bond holds the
2 strands together
- Explain semisconservative
replication and describe the Meselson-Stahl experiment
- Describe the process
of DNA replication and explain the role of helicase, single
strand binding protein, DNA polymerase, ligase, and primase.
- Explain what energy
source drives endergonic synthesis of DNA
- Define antiparallel
and explain why continuous synthesis of both DNA strands is
not possible
- Distinguish between
the leading strand and the lagging strand
- Explain how the lagging
strand is synthesized when DNA polymerase can add nucleotides
only to the 3' end
- Explain the role of
DNA polymerase, ligase, and repair enzymes in DNA proofreading
and repair
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- Describe early experimental
evidence that implicated proteins as the links between genotype
and phenotype
- Describe Beadle and
Tatum's experiments with Neurospora and explain the
contribution they made to our understanding of how genets
control metabolism
- Distinguish between
the "one gene~~one enzyme" hypothesis and the "one
gene~~one polypeptide" hypothesis and explain why the
original hypothesis was changed
- Explain how DNA differs
from RNA
- Explain how information
flows from gene to protein
- Describe where transcription
and translation occur in prokaryotes and in eukaryotes and
explain why it is significant that in eukaryotes, transcription
and translation are separated in space and time
- Define codon and explain
what relationship exists between the linear sequence of codons
on mRNA and the linear sequence of codons on mRNA and the
linear sequence of amino acids in a polypeptide
- List the three stop
codons and the one start codon
- Explain in what way
the genetic code is redundant and unambiguous
- Explain the evolutionary
significance of a nearly universal code
- Explain the process
of transcription including the 3 major steps of initiation,
elongation, and termination
- Explain the general
role of RNA polymerase in transcription
- Explain how RNA polymerase
recognizes where transcription should begin
- Specifically describe
the primary functions of RNA polymerase II
- Distinguish among mRNA,
tRNA, and rRNA
- Describe the structure
of tRNA and explain how the structure is related to function
- Given a sequence of
bases in DNA, predict the corresponding codons transcribed
on mRNA and the corresponding anticodons of tRNA
- Describe the wobble
effect
- Explain how an aminoacyl-tRNA
synthetase matches a specific amino acid to its appropriate
tRNA and describe the energy source that drives this endergonic
process
- Describe the structure
of a ribosome and explain how this structure relates to function
- Describe the process
of translation including initiation, elongation, and termination
and explain what enzymes, protein factors, and energy sources
are need for each stage
- Explain what determines
the primary structure of a protein and describe how a polypeptide
must be modified before it becomes fully functional
- Describe what determines
whether a ribosome will be free in the cytosol or attached
to rough ER
- Explain how proteins
can be targeted for specific sites within the cell
- Describe the difference
between prokaryotic and eukaryotic mRNA
- Explain how eukaryotic
mRNA is processed before it leaves the nucleus
- Describe some biological
functions of introns and gene splicing
- Explain why base-pair
insertions or deletions usually have a greater effect than
base-pair substitutions
- Describe how mutagenesis
can occur
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Chapter
Terms:
|
phages
double helix
semiconservative model
origins of replication
replication fork
DNA polymerase
leading strand
lagging strand |
DNA ligase
primer
primase
helicase
single-strand binding
protein
mismatch repair
nuclease
excision repair
telomerase |
|
|
auxotroph
one gene~one polypeptide
transcription
mRNA
translation
RNA processing
primary transcript
triplet codt
template strand
codon
reading frame
RNA polymerase
transcription unit
transcription factors
transcription initiation
complex |
TATA
box
terminator
5" cap
poly (A) tail
RNA splicing
intron
exon
spliceosome
domain
tRNA
anticodon
wobble
aminoacyl-tRNA
synthetases
rRNA |
P site
A site
E site
polyribosome
signal peptide
signal-recognition
particle
mutation
point mutation
base-pair substitution
missense mutation
nonsense mutation
insertion
deletion
frameshift mutation
mutagens
Ames Test |
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Chapter
Outline Framework
- DNA as the Genetic
Material
- The search for the
genetic material led to DNA
- Watson and Crick discovered
the double helix by building models to conform to X-ray
data
- DNA replication and
Repair
- During DNA replication,
base-pairing enables existing DNA strands to serve as
templates for new complementary strands
- A large team of
enzymes and other proteins carries out DNA replication
- Enzymes proofread
DNA during replication and repair damage to existing DNA
- The ends of DNA
molecules pose a special function
- The Connection between
Genes and Proteins
- The study of metabolic
defects provided evidence that genes specify proteins
- Transcription and
translation are the 2 main processes linking gene to protein
- In the genetic code,
nucleotide triplets specify amino acids
- The genetic code
must have evolved very early in the history of life
- The Synthesis and
Process of RNA
- Transcription is
the DNA-directed synthesis of RNA
- Eukaryotic cells
modify RNA after transcription
- The Synthesis of
Proteins
- Translation is the
RNA-directed synthesis of a polypeptide
- Signal peptides
target some eukaryotic polypeptides to specific locations
in the cell
- RNA plays multiple
roles in the cell
- Comparing protein
synthesis in prokaryotes and eukaryotes
- Point mutations
can affect protein structure
- What is a gene?
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