How do your genes determine your eye color?

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How do your genes determine your eye color?

• QOD

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Section 10-1

• Discovery of DNA

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DNA is The Genetic Material

• Evidence in favor of DNA
• Frederick Griffith 1928
• Transformation
• Avery, McCarty MacLeod 1944
• Hershey Chase 1952
• Bacteriophages

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LE 16-2
Mixture of heat-killed S cells and living R cells
Living S cells (control)
Living R cells (control)
Heat-killed S cells (control)
RESULTS
Mouse dies
Mouse healthy
Mouse healthy
Mouse dies
Living S cells are found in blood sample
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The Hershey-Chase Experiment
Section 1 Discovery of DNA
Chapter 10
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Draw and label a diagram of DNA. b) How does
your DNA store genetic information?

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Section 10-2

• DNA Structure

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What is DNA?

• Deoxyribonucleic acid
• Genetic information
• Traits
• Instructions/blue prints for proteins

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DNA Structure
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The Structural Model of DNA

• Rosalind Franklin (with Maurice Wilkins)
• X-ray diffraction
• Sugar-phosphate backbones on the side
• James Watson and Francis Crick
• Double-helix
• Nitrogen bases facing inward

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Make-up of DNA
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Makeup of DNA

• Nucleotides (3 parts)
• Deoxyribose
• Phosphate group
• Nitrogenous bases (4 different)
• Purines
• Adenine (A)
• Guanine (G)
• Pyrimidines
• Cytosine (C)
• Thymine (T)

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Section 2 DNA Structure
Chapter 10
DNA Nucleotides
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Nucleotide Structure

• Nucleotides join by bonding a deoxyribose of one
  nucleotide to the phosphate group of another
• Sugar and phosphate backbone of DNA
• Nitrogeneous base stick out to side
• Chargaffs rule
• Complementary bases

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III. DNA Structure

• Watson and Crick Model (1953)
• DNA is 2 strands
• Held together by weak hydrogen bonds
• H-bonds only form between certain bases
  (complementary base pairs)
• Double-helix shape

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Section 2 DNA Structure
Chapter 10
DNA Nucleotides
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Why does DNA replicate itself? When does DNA
replicate itself? How does DNA replicate itself?

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Section 10-3

• DNA Replication

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DNA Replicating
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I. DNA Replication

• Steps
• 1) Strands separate
• Replication fork
• Helicases
• 2) Base pairing
• DNA polymerase
• Complementary base pairing
• 3) Bonding of new nucleotides
• Covalent bonds
• Semiconservative replication

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DNA Replication
Section 3 DNA Replication
Chapter 10
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DNA Replication
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Section 3 DNA Replication
Chapter 10
Replication Forks Increase the Speed of
Replication
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Results

• Results
• Two identical strands of DNA
• Each has 1 original half and 1 new half
• Accuracy and Repair
• Proofreading
• Mutations
• Cancer

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Gene Mutations

• Point mutations
• Substitution
• Frameshift mutations
• Insertion
• Deletion

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Gene Mutations
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Compare and Contrast DNA to RNA.

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Section 10-4

• Protein Synthesis

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Introduction

• Genes, made of DNA, control traits
• DNA contains the information to make proteins
• The sequence of bases found in DNA contains the
  instructions for assembling a chain of amino
  acids (polypeptide)

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I. RNA

• Made of nucleotides, like DNA
• Differences
• Types
• mRNA
• tRNA
• rRNA

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Section 4 Protein Synthesis
Chapter 10
RNA Structure and Function
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How is transcription similar to DNA replication?
How is it different?

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Transcription of DNA
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II. Transcription

• Production of mRNA molecule
• Uses half of the DNA as a template
• First step in protein synthesis
• Occurs in Nucleus

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Transcription
Section 4 Protein Synthesis
Chapter 10
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Steps of Transcription

• Separation of DNA
• Promoters
• Formation of complementary RNA
• One strand
• RNA polymerase
• RNA will detach and DNA reconnects
• Termination signal

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Transcription
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More on Transcription

• Promoters regions of DNA that act as signals to
  start/stop transcription
• RNA editing
• Introns
• Exons
• Final product transcripts
• mRNA

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Introduction

• Proteins multiple chains of amino acids
• There are 20 different amino acids
• Structure of proteins
• Primary
• Secondary
• Tertiary
• Quartenary

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Fig. 2.17a
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Fig. 2.17b
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Fig. 2.17c
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Fig. 2.17d
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What is the next step in protein synthesis?How
is the mRNA read?

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The Genetic Code

• The mRNA is read by the ribosome three bases at
  a time
• Codon 3 consecutive bases that specify a single
  amino acid
• Example UCGCACGGU
• Proteins are made by reading and translating
  these codons

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Section 4 Protein Synthesis
Chapter 10
Genetic Code
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Translation

• Translation is the decoding of the mRNA molecule
  into a polypeptide chain
• Occurs at the ribosome
• Involves mRNA, tRNA, rRNA

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What is the result of a mutation (point or
frameshift) in the sequence if DNA?

• QOD

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Translation Assembling Proteins
Section 4 Protein Synthesis
Chapter 10
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Steps of Translation

• mRNA moves to ribosome
• Role of tRNA
• Each tRNA has an anticodon that is complimentary
  to mRNA codon
• Each type of tRNA carries a specific amino acid
• When the codon and anticodon match, an amino acid
  is brought over to the ribosome
• Codon AUG
• Anticodon UAC

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• Two codons read by the ribosome at the same time
• When two amino acids are at the ribosome, a
  peptide bond is formed between them
• 1st tRNA is released and ribosome moves to 3rd
  codon, where another amino acid is brought over
  by tRNA

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tRNA Anticodon
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tRNA Molecule-Amino Acid
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• Polypeptide continues to grow in this manner
  until the ribosome reaches a stop codon
• Codon that signals ribosome to stop translation
• UGA, UAG, UAA
• Protein is then released
• Polysomes multiple ribosomes

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Translation
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Gene Mutations
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