Date: January 5th, 2017 Aim #38: How does DNA replicate itself? HW: Daily Review of class notes. Packet- “DNA the Double Helix” Due Friday Do Now: Where is DNA found? What determines our traits? Where are genes located? What part of DNA carries the genetic code?

Aim #38: How does DNA replicate itself?

1) DNA Replication What does REPLICATE mean? (Hint) Replicate means to make a copy

2) What do we get when DNA replicates? Replication + Two New DNA Molecules

DNA Structure Review What is DNA composed of? Adenine Thymine Guanine 4 types Adenine Thymine Guanine Cytosine Deoxyribose Nucleotides

How do the Bases Pair Up? H Bonds All Teachers Go Crazy

3) DNA Structure What shape is this? Double-Helix Rosalind Franklin What scientists shared the Nobel Prize for their work on DNA? Maurice Wilkins Watson & Crick Rosalind Franklin

Watson and Crick (1953) Double Helix Model: DNA consists of two twisting chains of nucleotides in a ladder-like structure Model Explains: How DNA replicates and how it is used to make proteins

Maurice Wilkins and Rosalind Franklin used X-ray diffraction to understand the physical structure of the DNA molecule. https://www.youtube.com/watch?v=BIP0lYrdirI

5) What Process is Taking Place Here? Cell Division Why do our cells need to divide? REPAIR GROWTH

6) What does the DNA do before a cell divides? Genetic Information (DNA) DNA must replicate before a cell divides

7) Why must DNA replicate itself? DNA is the “Blueprint” for all cell activities. Each cell needs the entire “Blueprint” to function properly.

8) What are the Steps of DNA Replication? Step 1: Bonds between the bases are broken and the DNA Molecule is “Unzipped” G - C C - G T - A A - T DNA Molecule Bonds Broken G C C G T A A T 2 Separate Strands Enzymes

What are the Steps of DNA Replication? Step 2: Individual bases find their “match” on each single strand of DNA. G C T A C G A T G C C G T A A T 2 Separate Strands G C T A C G A T Base Pairing Enzymes Each strand is a Template for base pairing

What are the Steps of DNA Replication? Step 3: Bonds between the bases are formed G C G C C G C G T A T A A T A T G - C G - C C - G C - G T - A T - A A - T A - T Bonds Formed

DNA Replication C - G T - A A - T DNA Molecule C G T A A T 2 Separate G - C C - G T - A A - T DNA Molecule G C C G T A A T 2 Separate Strands G - C G - C C - G C - G T - A T - A A - T A - T Bonds Broken Base Pairing What is formed? 2 Identical DNA Molecules

9) Step 1: “Unzipping” the DNA The bonds between the bases are broken and the DNA molecule is “Unzipped”

10) Step 2: Bases Match Up Fill in the DNA molecule below. A C G T C

11) What is the final product of DNA Replication?

12) Where do we find that final product? Inside the nucleus

What Process is this? DNA Replication Each strand serves as a Template

Summary Questions Do you think DNA Replication is an accurate process? Why? What do you think would happen if DNA did not accurately replicate?