Transcript Chapter 11 DNA and the Language of Life (protein synthasis)

Chapter 11 DNA and the Language of
Life (protein synthesis)
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11.1
11.2
11.3
11.4
11.5
11.6
Genes are made of DNA honors
Nucleic Acid Sequence (A,T,G,C)
DNA replication = inheritance
1 Gene 1 Protein
Steps from Gene to Protein
Mutations in genes
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11.1 Genes are made of DNA
Mendel didn’t know about DNA
Griffith-1928-transforming factor
2 Bacteria
The harmful dead
changed the
harmless living into harmful living
Some “transforming factor” remained active
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11.1 Genes are made of DNA
► Avery-1944-
Transforming factor was DNA
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not protein
 Scientists were skeptical because
protein was very prevalent
► Hershey and Chase- Radioactive Virus
Experiments
DNA is
The genetic
material
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11.2 Nucleic Acid Sequence (A,T,G,C)
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Nucleotides (A,T,G,C) are monomers
(units) of nucleic acids
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3 parts: (sugar)
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deoxyribose(DNA) or ribose (RNA)
Phosphate group
Nitrogenous bases
pyramidines
purines
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11.2 Nucleic Acid Sequence
(A,T,G,C)
Nitrogenous bases
pyrimidines Single ring
(Cytosine, Thymine, U)
purines Double Ring (Guanine,A)
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11.2 Nucleic Acid Sequence
(A,T,G,C)
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1950’s
Franklin and Wilkins- DNA helix
Watson and Crick-Double helix
 Base
pairings
 C-G (Pyrimidine +Purine)
fix notes
 A-T (Pyrimidine +Purine)
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11.3 DNA replication = inheritance
Figure 11-9
During DNA replication,
the two strands of the
original parent DNA molecule,
shown in blue,
each serve as a template for
making a new strand,
shown in yellow.
 Replication results in
two daughter DNA molecules,
each consisting of
one original strand and
one new strand.
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11.3 DNA replication = inheritance
 Figure
11-10
 DNA replication
both directions
"bubbles."
bubbles merge
two daughter DNA
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11.4
1 Gene 1 Protein
The bases: A,T,G,C are the letters in the
language of Life
 The letters make up genes
 Sentences are the polypeptides (proteins)
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11.4
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1 Gene 1 Protein
Several RNA molecules play a part in the
intermediate steps from gene to protein
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11.4
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1 Gene 1 Protein
Each codon stands for an amino acid. (The table uses abbreviations
for the amino acids, such as Ser for serine.)
The codon AUG not only stands for methionine (Met), but also for
"start“.
There are also three "stop" codons that do not code for amino
acids, but signal the end of each genetic message.
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11.5 Steps from Gene to
Protein
Transcription: DNA to RNA
http://www.dnai.org/a/index.html
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Go to interactive screen- reading the code- putting it together -interactive
3 types of RNA
mRNA-messenger
tRNA-transfer
rRNA-ribosomal
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RNA splicing
Introns stay IN nucleus
 Exons EXit nucleus
 mRNA doesn’t
Contain introns
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11.5 Steps from Gene to
Protein
Translation: RNA to Protein
Figure 11-19
1.Translation begins with
the attachment of a
ribosome and the first tRNA
to a "start" (AUG) codon.
2. The ribosome then moves
along the mRNA. The
polypeptide elongates as an
amino acid is added for
each codon.
3. When the ribosome
arrives at a "stop" codon,
the completed polypeptide
is released
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