1. 11.1 Notes DNA

2. DNA notes outline I. Where found? II. Scientists: A. Hershey & Chase: B. Franklin: C. Watson & Crick: III. Parts of DNA nucleotide 1. phosphate 2. sugar= 3. nitrogen base 4 nitrogen bases: __ with __, __ with __ Example: IV. Structure twisted ladder: double helix: bonds: V. DNA replication 3 steps: mistakes

3. How does DNA effect your body? DNA is found in chromosomes which are located in the nucleus of cells DNA—Determines an organism’s traits, by determining structure of proteins in the body Proteins and enzymes—control most aspects of an organism

4. From Chromosomes to DNA

5. Important Discoveries Alfred Hershey and Martha Chase— performed an experiment proving that DNA is the genetic material inside cells

6. Rosalind Franklin Determined the shape of DNA to be helical (twisting) using x-rays.

7. James Watson and Francis Crick— discovered the shape of DNA (double helix) using Franklin’s research

8. All organisms—made up of the same nucleotides (building blocks of nucleic acids), just in different order Ex. All words are made up of the same letters, just in different order

9. Parts of a DNA nucleotide 3 parts of a nucleotide— 1. phosphate group 2. simple sugar (deoxyribose) 3. nitrogenous (or nitrogen) base 1. 2. 3.

10. 4 possible nitrogen bases adenine (A), guanine(G) = purines (2 rings) cytosine (C) and thymine (T) = pyrimidines (1) Complimentary base pairs— A pairs with T C pairs with G Adenine (A) Guanine (G)Thymine (T) Cytosine (C)

11. Example of Base-Pairing Example strand of DNA (Find each complimentary base pair for the strand of DNA) A—C—T—A—G—A—C—C—T—A—G—T | | | | | | | | | | | | T G A T C T G G A T C A

12. Structure of DNA molecule Nucleotides—join together in 2 long chains to form DNA If DNA is a ladder—Sugar and phosphate groups form the backbone and nitrogen bases form the rungs Double Helix—double strand, twisted ladder shape of DNA

13. Covalent bonds join sugars and phosphates Hydrogen bonds join A=T and C=G (2 between A and T, 3 b/t C and G)

14. DNA Replication DNA Replication—Whenever a cell divides, the DNA must first make an exact copy of itself (interphase) so each new cell will have a complete copy 1. DNA unzips (with enzyme) to form two single strands 2. Free floating nucleotides bond to each single strand 3. Two new and identical strands are formed

15. DNA Replication Original DNA Original DNA Strand Free Nucleotides New DNA molecule New DNA Strand New DNA molecule

16. DNA Replication Replication DNA

17. DNA Replication

18. Example of DNA Replication (Unzip the following strand of DNA, and write the two strands of DNA that would result from the replication) C—G—T—C—A—T—C—G—C—A—A—T—G | | | | | | | | | | | | | G—C—A—G—T—A—G—C—G—T—T—A—C Strand #1 C—G—T—C—A—T—C—G—C—A—A—T—G | | | | | | | | | | | | | G—C—A—G—T—A—G—C—G—T—T—A—C Strand #2 | | | | | | | | | | | | | G—C—A—G—T—A—G—C—G—T—T—A—C C—G—T—C—A—T—C—G—C—A—A—T—G

19. Mistakes in DNA replication Only 1 in 1 billion!! Just for fun: See how many words you can make from Deoxyribonucleic acid (record is 763)