1. What are the NAMES of the nucleotides? T.G.I.T. !!! 3/23/10 1. What are the NAMES of the nucleotides? 2. How do they pair up? 3. What are the 3 molecules that make up a nucleotide of DNA??

2. Practice for you!! Please answer on a new piece of paper! 1. How many types of nucleotides are in DNA?? 2. How are they different? 3. How are they the same? 4. What are the base pairing rules for DNA? 5. What is a double helix? 6. What is DNA? 7. Where is DNA found?? 8. What are the 3 molecules that make up a nucleotide of DNA?? 9. What sequence of bases would pair with the sequence: TGACTA 10. A sample of DNA is 31.5% adenine (A). Predict the approximate %s of G, T, and C.

3. 8.3 KEY CONCEPT DNA replication copies the genetic information of a cell!

4. What does replication mean???? To COPY!!!!

5. Why does a cell need to replicate its DNA??? Why does a cell need to REPLICATE its DNA?

6. Replication copies genetic information Remember this stuff?Remember this stuff? When does DNA replication occur????When does DNA replication occur????

7. Replication copies genetic information DNA is replicated during the S (synthesis) stage of the cell cycle!DNA is replicated during the S (synthesis) stage of the cell cycle! DNA needs a template, can’t do it alone!!!DNA needs a template, can’t do it alone!!! Base pairing rules  complementary copy!!!Base pairing rules  complementary copy!!! Each new cell gets a complete set of identical DNA.Each new cell gets a complete set of identical DNA.

8. Replication = process, DNA is copied during cell cycle (S phase of interphase) each new cell has its own full copy of DNA

9. Proteins carry out replication! DNA serves only as a template!DNA serves only as a template! Enzymes /proteins do the WORK of replication!Enzymes /proteins do the WORK of replication! 1. Enzymes unzip the double helix. 2. Free-floating nucleotides form H bonds with template strand. 3. result: 2 identical double strands!!! nucleotide The DNA molecule unzips in both directions.

10. Let’s see this in action... http://www.classzone.com/cz/books/bio_07/reso urces/htmls/animated_biology/unit3/bio_ch08_0 237_ab_dnarep.htmlhttp://www.classzone.com/cz/books/bio_07/reso urces/htmls/animated_biology/unit3/bio_ch08_0 237_ab_dnarep.html

11. p. 237: Label the STRUCTURE SIDE of the diagram! You are amazing You can do it! You are amazing! Word Bank: Newly synthesized strand of DNA Nitrogen Bases Sugar- phosphate Backbone DNA polymerase

12. Sugar- phosphate backbone Nitrogen Bases (A,T,G,C) DNA polymerase (enzyme) Newly synthesized strand of DNA (complementary)

13. Enzymes unzip dbl helix in 2 directions @ same time Nucleotides pair with exposed bases on template strand DNA polymerase bonds new n’tides together 2 molec’s of DNA, identical to original; each has 1 old & 1 new strand

14. –DNA polymerase enzymes bond the nucleotides together to form the double helix. –What kind of bonds hold the bases together???? DNA polymerase new strand nucleotide

15. . original strand new strand Two molecules of DNA Two new molecules of DNA are formed, each with an original strand and a newly formed strand. DNA replication is semi-conservative!

16. Let’s try it! We are going to extract DNA from Strawberries! YUM!We are going to extract DNA from Strawberries! YUM! You mustYou must –Follow directions, or it won’t work –Let’s see....40 points for Lab Participation –Follow directions!!! –Puzzle Activity After