1. DNA: The Molecule of Heredity

2. If the DNA of one cell is stretched out, it makes a 7 ft. long string There are about 5 trillion cells in the human body If you connected all the DNA together, it would be long enough that 10 hours it would take light over 10 hours to travel its length (ruptured bacteria)

3. Codes for your genes Located inside the nucleus in the form of chromosomes

4. NUCLEOTIDESDNA is made up of repeating units called NUCLEOTIDES Nucleotides have 3 parts: –Simple sugar –Phosphate –Nitrogenous base

5. A) Simple sugar = deoxyribose (the sugar gives it its name deoxyribonucleic acid) B) phosphate group C) 1 nitrogenous base –Adenine –Guanine –Cytosine –Thymine A B C

6. complementary base pairs Rules for Base Pairing: They are called complementary base pairs B. Adenine = Thymine (A = T) A. Cytosine Guanine (C G) the lines between the letters are hydrogen bonds

7. C G A A T G Sugar Phosphate Nitrogen Bases

8. Review QUESTIONS?? How many parts are there in a nucleotide? What is the simple sugar that makes up DNA? What pairs with A? What pairs with G?

9. QUESTIONS??? Find the complementary DNA strand that matches the following bases ATGA = ____________ TTGC = ____________

10. Fun Facts If you wrote down all of the bases in one cell, you would fill a stack of 1,000 phone books with A's, T's, G's and C's

11. Fun Facts If you unraveled all your chromosomes from all of your cells and laid out the DNA end to end, the strands would stretch from the Earth to the Moon about 6,000 times.

12. Why do you think DNA is called a double helix?

13. DNA Replication

14. DNA ReplicationThe DNA in the chromosome is copied in a process called DNA Replication

15. Replication of DNA During Replication, each strand serves as a pattern or template, to make a new DNA molecule just like the original

16. Question??? What is DNA Replication?

17. Replication of DNA

18. DNA Replication All DNA strands are read from the 5’ to 3’ end The 5’ end terminates in a phosphate group The 3’ end terminates in a sugar molecule (deoxyribose)

19. DNA Replication Okazaki Fragments are short, newly synthesized DNA fragments that are formed on the lagging template strand (3’ to 5’ side) during DNA Replication

20. DNA Replication The leading strand is continuously built in the 5’ to 3’ direction DNA polymerase can only add new nucleotides to a free 3’ end of a growing chain or the Lagging strands. These are discontinuous with Okazaki fragments coming in to fill in the gaps

21. Biology Humor

22. Replication of DNA This process continues until the entire molecule has been unzipped and replicated. Each new strand formed is a complement of the original – part old, part new

23. Compare the 2 new strands formed through DNA Replication?

24. DNA Review Basic structure is made up of a nucleotide –Phosphate –Sugar Deoxyribose –Nitrogen Base A pairs with T G pairs with C DNA Replication –Copying of DNA –DNA Helicase unzips the DNA –Polymerase attaches the free nitrogen base –Works the leading strand (5’ to 3’) –Has to work backwards on the lagging strand (3’ to 5’) & fill in the gaps with Okazaki fragments