DNA The Blueprint of Life Rosalind Franklin 1952
DNA "The Blueprint of Life"
Rosalind Franklin • 1952, Rosalind Franklin used x-ray crystallography to take a picture of DNA
What is DNA? How is it like your own individual Barcode?
Rosiland Franklin X-ray Diffraction use of photo 51 X-ray diffraction data helped solve the structure of DNA Indicated that DNA was a double helix
X-Ray chyrstallography
A little history lesson…. • 1953: James Watson (twenty-five years old at the time) and Francis Crick (right) established that the structure of a DNA was a double helix. • In 1962, Watson, Crick and Maurice Wilkins shared the Nobel Prize • Rosalind Franklin, who had died very young in 1958, was not included in the Prize despite her work being crucial to Watson and Crick.
DNA stands for. . . Deoxyribo. Nucleic Acid
●Codes for your genes (traits) ●Made of repeating subunits called nucleotides
What is a nucleotide? Has three parts: 1. PHOSPHATE 2. DEOXYRIBOSE (sugar) 3. BASE (A, T, G, C) Phosphate Base Sugar
Base-Pair Rule Adenine <==> Thymine Guanine <==> Cytosine • The sides of the DNA ladder are phosphate & sugar • The steps of the ladder are made of nitrogen bases that are held together by hydrogen bonds
Base Pair Rule One side: Other side: A T C A T G C G G G T A C G C C C
Nitrogen Bases Phosphate and Sugar Two strands form the DOUBLE HELIX
What is the relationship between GENES and DNA?
How the Code Works The combination of A, T, G, C (bases) determines what traits you might have. . . C A T = purple hair T A C = yellow hair
Think of the bases of DNA like letters. Letters form words. . Words form sentences. . *endless combinations
Genetic Code • “Words” and “Sentences” are called genes. • Humans have 20, 000 – 25, 000 genes that code for traits. • These genes tell a cell what proteins to make. • It is the proteins that give your traits. For example, brown hair, blue eyes, etc.
Let's Review What We Know About DNA 1. DNA stands for: De _____ ribo ______ acid 2. What is the shape of DNA? _______ 3. Who established the structure of DNA? ______ and _______ 4. Adenine always pairs with ________
6. Guanine always pairs with _______ 7. What is the complementary sequence: C A T T A G 8. The two sides of DNA are held together by _______ bonds. 9. DNA is composed of repeating subunits called ___________ 10. What are the 4 bases that make up the rungs of the DNA ladder? __________
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