1. Today’s Objectives Content Objective: Students will: Complete a lab activity that has them extracting DNA from a strawberry. Build nucleotides (monomers) and put them together to form a DNA strand. Take notes on RNA and transcription. Language Objective: Students will: Summarize their notes on RNA & Transcription. Collaborate with a partner to build a segment of DNA. Listen and follow lab procedures. Student learning Outcome: Creative Communication Critical Thinking Collaborative

2. Let’s review from last time! What was Rosalind Franklin’s contribution to the discovery of DNA? TARGET 1 Used x-ray crystallography to figure out DNA structure. What evidence did Watson and Crick use to explain the structure of DNA? TARGET 2 Base Pairings (Chargaff) x-ray data

3. DNA Replication Why does our body need to make copies of DNA? Reproduction Replacement Cell Division

4. When does replication happen? The beginning of the cell cycle, during interphase (S phase)

5. DNA Replication Happens in three steps: 1.DNA strand “unzips” 2.Free nucleotides attach to each single strand 3.DNA “rewinds”

6. DNA ‘unzips’ DNA strand is ‘unzipped’ by helicase enzyme (protein) * breaks hydrogen bonds between base pairs * this happens at multiple spots all along the DNA strand

7. Nucleotides attach DNA Polymerase binds free floating complementary nucleotides to each single strand. *Happens going in one direction for one strand and in the opposite direction for the other.

8. Two Identical Strands of DNA Both strands are proofed and then recoil into identical double helix strands

9. Semi-conservative Model DNA consists of 1 ‘old’ strand and 1 ‘new’ strand Original (old) strand serves as template for creating new strand

10. How does DNA copy itself? http://www.ck12.org/biology/DNA-Structure- and-Replication/enrichment/DNA-Replication- Overview/?referrer=featured_content http://www.ck12.org/biology/DNA-Structure- and-Replication/enrichment/DNA-Replication- Example-1/?referrer=concept_details

11. Materials Coffee filter 125 mL flask Coffee stirrer Graduated cylinder Test tube Ziploc bag

12. Strawberry SMASH!

13. Filtering Apparatus

14. End result! Rubbing alcohol DNA Strawberry extract

15. Clean up directions Throw away coffee filter & stirrer Throw away bag if it has a hole Rinse out materials in the front sink Throw away any solids in the trash Place glassware to dry