DNA and RNA Objective: To learn the structure and function of DNA

What do the following pictures have in common? Spider Bacteria

Race Horses Flowers

Types of DNA _____________ DNA Found in the ___________ _____________ DNA (mtDNA) Only inherited from the __________________ side Nuclear DNA nucleus Mitochondrial Mitochondria maternal

Who discovered the structure of DNA? Watson and Crick knew DNA was made up of nucletides X-ray diffraction Uncovered the basic structure of DNA James Watson and Francis Crick In 1953 were given credit

Sources of DNA Blood Sperm Saliva Root of Hair Body tissue Bones Teeth Epithelial cells from urine

Nitrogen containing base Nucleotides Made up of: A A _________ ___________ _____________ Deoxyribose Sugar Nitrogen containing base Phosphate

Deoxyribonucleic Acid DNA Structure Compared to a ______ Rungs = __________ Backbone = ____________ and ____________ Two sides held together by ______________ DNA = ladder Nitrogen Bases Deoxyribose Sugar Phosphate Hydrogen bonds Deoxyribonucleic Acid

Nitrogenous Bases Purines ________ ring system Pyrimidines __________ Guanine Pyrimidines _________ ring system Cytosine ___________ Double Adenine Single Thymine

Base Compliments Purines pair with pyrimidines Meaning ________________ Adenine pairs with thymine Cytosine pairs with guanine

Erwin Chargaff Found that: Adenine and _________ were found in equal amounts Guanine and ___________ were found in equal amounts Thymine Cytosine

DNA Overview

Erwin Chargaff Measured the levels of the nitrogen bases What conclusions can you make from the chart below? DNA Source Adenine Thymine Guanine Cytosine Calf Thymus 1.7 1.6 1.2 1.0 Beef Spleen 1.5 1.3 Yeast 1.8 1.9 Bacillus 1.1 2.6 2.4

DNA Overview DNA Hydrogen bonds, double helix, nucleotides, nitrogen bases, pentose sugar, phosphate, backbone, base compliment rule

DNA Overview DNA Hydrogen bonds, double helix, nucleotides, nitrogen bases, pentose sugar, phosphate, backbone, base compliment rule

Complimentary DNA Strands ACCCTTACT GTAGTGAG TTCCGGCCT AAACTAT

Semi-Conservative Replication How does this prevent mutations?

DNA Replication Map Helicase breaks hydrogen bonds Helicase separates strands Free nucleotides attach to base compliments Hydrogen bonds form The original strands are used to make new copies. Results in two identical strands Why is this referred to as semi conservative replication?

Restriction Enzymes Cut DNA into __________ at a _______ base __________ fragments specific sequence

Restriction Enzyme Example #1 Base Sequence: A T A C G T A C C G T T A T G C A T G G C A Restriction Enzyme cuts at TAC Resulting fragments: How many fragments did you end up with?

Restriction Enzyme Example #2 Base Sequence: C G C A T T A C A T A G C G T A A T G T A T Restriction Enzyme cuts at CAT Resulting fragments: How many fragments did you end up with?

Restriction Enzyme Example #3 Base Sequence: A T T G A G C C G G A G T A A C T C G G C C T C Restriction Enzyme cuts at GAG Resulting fragments: How many fragments did you end up with?

Creating a DNA Fingerprint http://www.pbslearningmedia.org/resource/tdc02.sci.life.gen.sheppard/forensic-dna-analysis/ http://www.biology.arizona.edu/human_bio/problem_sets/dna_forensics_2/07c.html

Gel Electrophoresis http://www.youtube.com/watch?v=mN5IvS96wNk Simulation http://www.youtube.com/watch?v=Fi63VjfhsfI

Electrophoresis Map Gel Electrophoresis What is it used for? Matching fragments? Large fragments? Small fragments?

Electrophoresis What is it used for? Large fragments Small fragments Separate DNA Fragments Determine if DNA fragments match Large fragments More base pairs Move less Small fragments Fewer base pairs Move further

Reading Gels Lanes Matching bands ___________ have the same # of ____________ Indicates ______ fragments came from __________ DNA fragments Base pairs Wells Bands DNA the same source

What can you determine?

Identify . . . . .

Do any of the samples match?

OJ Simpson http://www.youtube.com/watch?v=Ojq0y5c4pWI (DNA Examination) http://www.youtube.com/watch?v=H4sfb6_Wswg (Case Info) http://www.youtube.com/watch?v=f98j9X4_OrI (Glove evidence)

DNA Technology OJ Simpson Joseph Michael Simpson Our Case The Accused Case Details How DNA was Obtained How DNA was Used in the Case OJ Simpson Joseph Michael Simpson Our Case