DNA

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DNA
The fingerprint thats inside your body!
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DNA

• DNA stands for Deoxyribonucleic Acid
• It is a nucleic acid that stores and transmits
  the genetic information from one generation of
  organisms to the next

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Deoxyribose a type of sugar Nucleic Acid a
macromolecule that contains H, O, N, C, P
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Nitrogenous Bases

• Adenine
• Cytocine
• Guanine
• Thymine

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Nucleotides

• Nucleotides are joined together to form long
  chains

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Where is DNA? DNA is found in the nucleus of
eukaryotic cells and the cytoplasm of prokaryotic
cells.
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DNA
Looks like a twisted ladder called a double
helix
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The double helix shape was discovered in the
early 1950s
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Important Researchers

• Rosalind Franklin and Maurice Wilkins
• James Watson and Francis Crick
• Erwin Chargaff

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The double helix shape was discovered in the
early 1950s
Rosalind Franklin took the first picture in 1952
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She used x-rays and it gave clues about the shape
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Watson and Crick arecredited with the DNA
discovery
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They used the photo to make the first model of
DNA
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DNA is a very long molecule made of nucleotides
(3 parts) 1. 5-Carbon sugar 2. Phosphate
group 3. Nitrogen-containing base
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4 Nitrogen-containing bases Adenine Always
paired together Thymine Cytosine Always
paired together Guanine
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Structure of the DNA Molecule
This is deoxyribose
This is phosphate
Nitrogen-containing bases
Green can only go with Red
Purple can only go with Yellow
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Terminology of DNA
DNA a large molecule that stores and transmits
genetic info.
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Terminology of DNA
DNA a large molecule that stores and transmits
genetic info. Chromatin uncoiled form of DNA
(cell is in interphase)
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Terminology of DNA
DNA a large molecule that stores and transmits
genetic info. Chromatin uncoiled form of DNA
(cell is in interphase) Chromosome coiled DNA
with proteins that form during cell division to
transmit genetic info
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Terminology of DNA
Gene A section of a chromosome that is a code
to make a protein or define the action of a
protein.
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DNA Numbers
46 The number of chromosomes in the human cell
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DNA Numbers
46 The number of chromosomes in the human
cell 300 3000 The number of genes on a
single chromosome
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DNA Numbers
46 The number of chromosomes in the human
cell 300 3000 The number of genes on a
single chromosome 50,000 100,000 total genes
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DNA Numbers
46 The number of chromosomes in the human
cell 300 3000 The number of genes on a
single chromosome 50,000 100,000 total
genes 3,000,000,000 Number of base pairs in
the whole human genome
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Structure of a Chromosome
Nucleus
Cell
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Structure of a Chromosome
Nucleus
Cell(During metaphase)
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Structure of a Chromosome
Nucleus
Cell
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Structure of a Chromosome
Nucleus
Cell
Base Pairs A, G, C, T
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Structure of a Chromosome
Nucleus
Cell
Double Helix
Base Pairs A, G, C, T
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Structure of a Chromosome
Nucleus
Cell
Double Helix
Histone A Protein DNA wraps around
Base Pairs A, G, C, T
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Structure of a Chromosome
Nucleus
Cell
Nucleosome DNA wrapped around the histone
Double Helix
Histone A Protein DNA wraps around
Base Pairs A, G, C, T
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Structure of a Chromosome
Nucleus
Cell
Coils
Nucleosome DNA wrapped around the histone
Double Helix
Histone A Protein DNA wraps around
Base Pairs A, G, C, T
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Structure of a Chromosome
Nucleus
Cell
Coils
Nucleosome DNA wrapped around the histone
Supercoils
Double Helix
Histone A Protein DNA wraps around
Base Pairs A, G, C, T
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Structure of a Chromosome
Chromosome
Nucleus
Cell
Coils
Nucleosome DNA wrapped around the histone
Supercoils
Double Helix
Histone A Protein DNA wraps around
Base Pairs A, G, C, T
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Structure of a Chromosome
Chromosome
Nucleus
Centromere
Cell
Coils
Nucleosome DNA wrapped around the histone
Supercoils
Double Helix
Histone A Protein DNA wraps around
Base Pairs A, G, C, T
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Base Pairing

• Adenine pairs with Thymine
• Cytosine pairs with Guanine

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Replication of DNA

• DNA consists of complimentary strands
• Before a cell can divide it must replicate its
  DNA

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Replication is a three step process

• Enzymes unzip the two strands
• Complementary bases are inserted
• Bases are proofread

Click on the box for the movie
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Questions for the Margins of your Cornell Notes

• What does DNA stand for?
• What does DNA do?
• What is DNA composed of?
• What are nucleotides
• Who did important research on DNA?

• What is base pairing?
• Which bases pair with each other?
• How does DNA copy itself?