dna (deoxyribonucleic acid)
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
DNA(Deoxyribonucleic Acid)History and Structure
C10L28C12
During Mitosis we can see Chromosomes
Chromosomes and DNA
Chromosomes are made of
DNA
Chromosomes and DNA
Item 5
DNA HistoryDNA Structure
Today’s Goals
What is DNA?
DNA Nitrogen BasesChargaff's Rule
Item 1Item
2Item 3Item
4
DNA holds all the genetic information that determines an
organism’s traits.
What is DNA?
Hair Color
Eye Color
Height
Skin Tone
Within the structure of DNA is the information for life—the complete instructions for manufacturing all
the proteins for an organism.
What is DNA?
o 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
Item 5
DNA HistoryDNA Structure
Today’s Goals
What is DNA?
DNA Nitrogen BasesChargaff's Rule
Item 1Item
2Item 3Item
4
Important clues to the structure of DNA
1. Twisted strands (helix)2. Angle suggested 2
strands ( double-helix)3. Nitrogen bases near the
center of the molecule
Rosalind FranklinStudied DNA structure with X-ray diffraction
1952
James Watson
and Francis CrickBuilt a DNA model based on
the clues from Franklins X-ray diffraction
1953
Item 5
DNA HistoryDNA Structure
Today’s Goals
What is DNA?
DNA Nitrogen BasesChargaff's Rule
Item 1Item
2Item 3Item
4
DNA is a Double HelixA 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 StructureComposed of 3 parts
Phosphate
DeoxyriboseSugar
NitrogenBase
•There are 4 possible bases.•Broken down into 2 categories
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.
Item 5
DNA HistoryDNA Structure
Today’s Goals
What is DNA?
DNA Nitrogen BasesChargaff's Rule
Item 1Item
2Item 3Item
4
PURINESPurines have two
ringsPyrimadines have
one ring
PYRIMIDINES
Types of Nitrogen basesThere are two types of nitrogen bases
PURINES
PYRIMIDINES
Types of Nitrogen basesThere are two types of nitrogen bases
Item 5
DNA HistoryDNA Structure
Today’s Goals
What is DNA?
DNA Nitrogen BasesChargaff's Rule
Item 1Item
2Item 3Item
4
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
1 PURINE MUST BOND TO 1 PYRIMADINE
Guanine only bonds to
Cytosine
Chargaff’s Rule – Base Pairing
Adenine only bonds to
ThymineAt The
Grand Canyon
OVERVIEW