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3. 2 Nucleic Acids Genetic information is stored by nucleic acids.Genetic information is stored by nucleic acids. DNA (deoxyribonucleic acid)DNA (deoxyribonucleic acid) RNA (ribonucleic acid)RNA (ribonucleic acid)

4. 3 Nucleic Acids For most organisms:For most organisms: –DNA stores the genetic info. in the nucleus. –RNA is in the cytoplasm. Some viruses and prokaryotes store information in RNA.Some viruses and prokaryotes store information in RNA.

5. 4 Watson & Crick’s Model http://www.yout ube.com/watch?v =_ptCxkeaxYY&f eature=related

6. NUCLEUS with DNA Histone

7. 6 The Shape of the Molecule DNA is a very long polymer. The basic shape is “twisted ladder or a double helix.

8. 7 Nucleic Acid DNA is a polymer made up of the monomers called nucleotides. Each nucleotide contains –A pentose sugar –A phosphate –An organic base nucleotide

9. A nucleotide 8

10. 9 Nucleic Acid The backbone of the molecule is alternating phosphates and a pentose sugar The teeth are nitrogen bases. phosphate deoxyribose bases

11. 10 Two Stranded DNA Covalent Bonds Hydrogen Bonds

12. The sugar Ribose in RNA 11 Deoxyribose in DNA

13. The phosphate H 3 PO 4 12

14. 13 Nitrogenous bases Nitrogenous bases Cytosine C Thymine T Adenine A Guanine G DNARNA Cytosine C UracilU Adenine A Guanine G

15. CHARGAFF’S RULE A = T G = C Image from: http://evolution.berkeley.edu/evosite/evo101/images/dna_bases.gif _________ At time no one knew why… now we know its because Adenine always bonds across with____________ Guanine always bonds across with ____________ THYMINE CYTOSINE

16. Purines (2 rings) Pyrimidines (1 ring) A G C T Phospha te group Deoxyribose sugar Nitrogen bases =“Steps of ladder” © Pearson Education Inc, publishing as Pearson Prentice Hall. All rights reserved

17. 16 Chargraff’s Rule: Adenine and Thymine always join together A T Cytosine and Guanine always join together C G AKA “Complementary Base-Pairing” The width in between each backbone is 3 rings (A with T; C with G)

18. 17 DNA by the Numbers Each cell has about 2 meters of DNA. The average human has 75 trillion cells. The average human has enough DNA to go from the earth to the sun more than 400 times. The earth is 150 billion m or 93 million miles from the sun.

19. Closure Draw a quick diagram of DNA. Label all the parts. Label the bonds. Circle one nucleotide. 18

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