1. Bellwork: 2/14 Put your phone up  Week 2/11 - 2/15
Hypothetically…if you had a genetic disorder that runs in your family (cancer, Huntington’s, Alzheimer's, Parkinson’s, heart disease, etc…), would you get genetic testing to figure out if you would develop the disorder too? Why or why not?
Do you know who discovered DNA? If yes, who?
Draw DNA (the best you can) 

2. Today:
Bellwork
Unit 5, Part 1 Notes
DNA Video

3. Materials
Unit Book

4. This Week: Monday: BioTech Lab Prep Tuesday: BioTech Lab
Wednesday: Pt. 1 Notes & Video
Friday: Pt. 2 Notes

5. Homework
None 

6. Unit V: DNA & Molecular Genetics

7. Part 1: DNA Structure & History

8. DNA DNA = deoxyribonucleic acid Function of DNA:
Storage of genetic information
Structure of DNA:
Made of 2 strands
Each strand is a polymer (chain) of nucleotides

9. Nucleotide A nucleotide has three components: Phosphate group
Deoxyribose sugar
5 Carbon sugar
Nitrogenous base

10. Nitrogenous Bases Purines – double ring
(A) Adenine
(G) Guanine
Pyrimidines – single ring structure
(T) Thymine
(C) Cytosine

11. Double Helix Two strands of nucleotides are twisted in a helical shape
The two strands are antiparallel
Meaning they run in opposite directions
The strands are held together by hydrogen bonds
A weak bond between the strands

12. Think!
Think of an everyday analogy that would illustrate the term antiparallel. Explain how this everyday analogy is related to the antiparallel nature of the two strands of DNA.

13. Chargaff
Edwin Chargaff, an American Biochemist examined the % composition of nitrogenous bases (adenine, guanine, thymine and cytosine) in different organisms

14. Chargaff’s Data Species Adenine (%) Thymine (%) Guanine (%)
Cytosine (%)
Human
31.0
31.5
19.1
18.4
Fruit Fly
27.3
27.6
22.5
Corn
25.6
25.3
24.5
24.6
Yeast
23.0
23.3
27.1
26.6
Bacteria
24.3
25.5

15. Key Observations
Guanine approximately equal to Cytosine; Adenine approximately equal to Thymine
Suggests that G always pairs with C and A always pairs with T
In other words, a purine always pairs with a pyrimidine
These pairs are referred to as complementary base pairs

16. Complementary Base Pairing
Purine pairs with Pyrimidine
Results:
Double helical structure having a constant diameter

17. Significance of Complementary Base Pairs
Based on complementary base pair rules, the sequence of nucleotides on one strand determines the sequence of nucleotides on the other strand

18. Sample Problem Strand 1: A T G C A C T A G C A A Strand 2:
For the nucleotide sequence of the DNA strand below, write on your note-guide the complementary strand. Remember A pairs with T and G pairs with C:
Strand 1: A T G C A C T A G C A A
Strand 2:

19. Significance of DNA Watch the video and answer the questions