DNA "The Blueprint of Life"

Rosalind Franklin 1952, Rosalind Franklin used x-ray crystallography to take a picture of DNA

X-Ray cyrstallography

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... DeoxyriboNucleic 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 Sugar Base

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: A T A T C A T G C G G G Other side: T A T A G T A C GC 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 determines what traits you might have..... C A T C A T = purple hair T A C 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 you 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 _______________ 5. The sides of the DNA ladder are deoxyribose and _______________

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? ____________________

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 _______________ 5. The sides of the DNA ladder are deoxyribose and _______________

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? ____________________