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DNA (Deoxyribonucleic Acid). History and Structure. C10L28C12. Chromosomes and DNA. During Mitosis we can see Chromosomes. Chromosomes are made of DNA. Chromosomes and DNA. Today’s Goals. Item 1. Item 2. DNA History. DNA Structure. What is DNA?. DNA Nitrogen Bases. Chargaff's Rule.
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DNA(Deoxyribonucleic Acid) History and Structure C10L28C12
Chromosomes and DNA During Mitosis we can see Chromosomes Chromosomes are made of DNA
Today’s Goals Item 1 Item 2 DNA History DNA Structure What is DNA? DNA Nitrogen Bases Chargaff's Rule Item 3 Item 4 Item 5
What is DNA? DNA holds all the genetic information that determines an organism’s traits. Height Hair Color Skin Tone Eye Color
What is DNA? Within the structure of DNA is the information for life—the complete instructions for manufacturing all the proteins for an organism. • DNA achieves its control by determining the structure of proteins. • Enzymes (a type of protein) control the chemical reactions needed for life. • Eating, running, even thinking
Today’s Goals Item 1 Item 2 DNA History DNA Structure What is DNA? DNA Nitrogen Bases Chargaff's Rule Item 3 Item 4 Item 5
Rosalind Franklin 1952 Studied DNA structure with X-ray diffraction Important clues to the structure of DNA • Twisted strands (helix) • Angle suggested 2 strands ( double-helix) • Nitrogen bases near the center of the molecule
James Watson and Francis Crick Built a DNA model based on the clues from Franklins X-ray diffraction 1953
Today’s Goals Item 1 Item 2 DNA History DNA Structure What is DNA? DNA Nitrogen Bases Chargaff's Rule Item 3 Item 4 Item 5
DNA is a Double Helix A double helix looks like a twisted ladder.
The Double Helix Building Blocks A DNA strand is a polymer. They are very long! It’s length is what allows DNA to hold so much information The repeating subunits of DNA are called nucleotides
Nucleotide Structure Composed of 3 parts • There are 4 • possible bases. • Broken down into • 2 categories Phosphate Nitrogen Base Deoxyribose Sugar
Nucleotide Structure • The phosphate groups and deoxyribose (sugar) molecules bond to form the backbone of the chain • The nitrogenous bases stick out like the teeth of a zipper.
Today’s Goals Item 1 Item 2 DNA History DNA Structure What is DNA? DNA Nitrogen Bases Chargaff's Rule Item 3 Item 4 Item 5
Types of Nitrogen bases There are two types of nitrogen bases Purines Pyrimidines Purines have two rings Pyrimadines have one ring
Types of Nitrogen bases There are two types of nitrogen bases Purines Pyrimidines
Today’s Goals Item 1 Item 2 DNA History DNA Structure What is DNA? DNA Nitrogen Bases Chargaff's Rule Item 3 Item 4 Item 5
How the double helix is formed Nitrogen bases bond to one another to connect the two strands But only certain bases can bond to one another
Chargaff’s Rule – Base Pairing 1 Purine must bond to 1 pyrimadine Adenine only bonds to Thymine Guanine only bonds to Cytosine The At Grand Canyon