1. Nucleic Acids
Big Idea 3: Living systems store, retrieve, transmit, and respond to info essential to life processes.

2. Essential Knowledge
3A1: DNA, and in some cases RNA, is the primary source of heritable information.

3. Nucleic Acids Store and transmit hereditary information
Amino acid sequence of a polypeptide is programmed by a unit of inheritance called a gene
Genes are found on chromosomes.

4. Nucleic Acids Large, complex molecules composed of C, O, H, N, and P.
2 types are RNA, ribonucleic acid and DNA, deoxyribonucleic acid.

5. DNA

6. RNA

7. Prokaryotes Earliest cells Smaller than Eukaryotes!
No nucleus (home for DNA)

8. Is housed in a region called the nucleoid
Prokaryotic DNA
Is housed in a region called the nucleoid

9. Prok. DNA Is usually small and circular
Has plasmids: small, extra-chromosomal, double stranded, and circular DNA

10. Viruses and Eukaryotes can have plasmids too…

11. Led to double helix shape discovery by Watson and Crick
Herstory
Rosalind Franklin: British scientist (working in Maurice Wilkins lab) who took an X ray diffraction image of DNA, 1952
Led to double helix shape discovery by Watson and Crick
Photo 51

12. Double Helix Structure
HIStory
Watson and Crick used Franklin’s image to create the double helix DNA model in 1953.
Won Nobel Prize in 1962,w/ Wilkins.
Double Helix Structure

14. Nucleic Acid Structure
Made of nucleotides; both RNA and DNA.
Each nucleotide contains:
1 Phosphate Group
1 Sugar
1 Nitrogen Base

15. Makes up a part of the DNA/RNA backbone
Phosphate
PO4
Makes up a part of the DNA/RNA backbone

16. Sugar In DNA, sugar is deoxyribose In RNA, sugar is ribose
Binds to Nitrogen Base
Is in backbone of DNA/RNA

17. (c) Nucleoside components: sugars
Fig. 5-27c-2
Sugars
Figure 5.27 Components of nucleic acids
Deoxyribose (in DNA)
Ribose (in RNA)
(c) Nucleoside components: sugars

18. Conserved Through Evolution!
DNA Nitrogen Bases
Adenine
Thymine
Guanine
Cytosine
Conserved Through Evolution!

19. DNA Base Pairing Rules (Chargaff’s Rules)
A only binds with T
C only binds with G
H bonds hold Nitrogen bases together

20. RNA Nitrogen Bases
Adenine
Cytosine
Guanine
Uracil
NO Thymine!

21. Pyrimidines: Single Ring Structure: CTU
Fig. 5-27c-1
Nitrogenous bases
Pyrimidines
Cytosine (C)
Thymine (T, in DNA)
Uracil (U, in RNA)
Pyrimidines: Single Ring Structure: CTU
Purines
Figure 5.27 Components of nucleic acids
Adenine (A)
Guanine (G)
Purines: Double Ring Structure, GA
(c) Nucleoside components: nitrogenous bases

22. DNA: Double Stranded, RNA Single Stranded

23. DNA is AntiParallel

24. 3’ carbon and 5’ carbon bind to PO4 phosphodiester linkage
Fig. 5-27ab
3’ carbon and 5’ carbon bind to PO4 phosphodiester linkage
5' end
5'C
3'C
Nucleoside
Nitrogenous
base
5'C
Phosphate
group
Figure 5.27 Components of nucleic acids
3'C
Sugar
(pentose)
5'C
3'C
(b) Nucleotide
3' end
(a) Polynucleotide, or nucleic acid

25. DNA Replication
DNA provides directions for its own replication  ensure continuous inheritance of DNA

26. DNA Replication Before a cell divides  must duplicate its DNA.
Each strand of DNA will serve as a template/model for a new strand of DNA (semiconservative).

27. DNA Replication 1st Step
DNA Helicase
Enzyme called DNA helicase unzips and unwinds a portion of DNA.
Enzyme helps breaks apart H connect N bases. (A,T,C,G)

28. DNA Replication: 2nd Step
2nd enzyme called DNA polymerase III comes along and begins to add complementary base pairs to nitrogen bases.
Works in 5’ to 3’ fashion…
Video Clip!

29. Other Enzymes Involved:
DNA Replication
Other Enzymes Involved:
Ligase: Glues back sugar-phosphate backbone
Topoisomerase: Regulates overwinding/ underwinding of DNA by cutting backbone

30. http://highered. mcgraw-hill

31. Practice!
If one side of DNA reads CTCT, what would the complement side of DNA read? Write down on paper!

32. GAGA!

33. Then, The Cell Divides…
Mitosis: Makes 2 identical diploid (2 copies of chromosomes) cells from 1 parent cell: IPMAT