What Is This Stuff??? Get a stamp on R&C q’s Entry Task: What is Papain?

“What is This Stuff?” R & C q’s 1. What do you think was the purpose of each procedural step? Add this to the “why” column of your procedure chart. 2. If we had used cow liver, peas or mushrooms, how would our results have compared? 3. This protocol (procedure) isolated DNA, not protein. How do you know that? 4. Did the isolated DNA look like you expected? What did you expect it to look like? 5. How might you prove that DNA is present in all living cells and not present in non living things? 6. How might you modify this protocol (procedure) to get better results? 7. What is papain?

Clips of DNA KEY CONTENT: DNA Structure LEARNING TARGET: I can use models to learn about DNA’s structure

Clips of DNA Part I: DNA’s Structure “What is the structure of DNA?” Make a box about ½ a page in size under the Investigative Question. Read “The Code in DNA” (page 406) together; write key terms, make sketches, etc. about DNA’s structure in your note box.

Clips of DNA Part I: DNA’s Structure “What is the structure of DNA?” Use the colored paper clips to build a model of DNA. – Your model should be 15 nucleotides long and must contain all 4 nucleotides.

Clips of DNA Part I: DNA’s Structure “What is the structure of DNA?” Record the sequence of your DNA model in your lab notebook. – Write your sequence horizontally – For ease, just record the first letter of each nucleotide (ex: Adenine = A) Have your neighbor check your work.

Clips of DNA Part I: DNA’s Structure Read “Double The Code” together; write key terms and ideas in your note box. Shorten your DNA model to 8 nucleotides. Be sure it contains at least one of each nucleotide. Record this new sequence vertically in your lab notebook

Clips of DNA Part I: DNA’s Structure Build a new DNA strand next to your 8 nucleotide strand. – Make sure your new strand COMPLEMENTS your 8 nucleotide strand! – Record this complementary strand next to the original strand. Now make a careful sketch of your double stranded DNA model. Label the nucleotides and show the helical structure of DNA (refer to figure 8.11 for help!)

Clips of DNA Check for Understanding! Read “Copying DNA” together. (page 413) Make a new note box. Record notes as we read. – “Unzip” your 6 nucleotide model of DNA. – Replicate your DNA by complementing the bases. – Have your neighbor check your work.

Clips of DNA R & C q’s! 1.What is DNA polymerase? 2.When does DNA replication occur? 3.Why must DNA replication be accurate?

Clips of DNA  During replication in human cells, DNA polymerase adds nucleotides at a rate of 50 per second  Initially, the error rate in newly replicated DNA is about 1 error in 10,000 base pairings  After proofreading by DNA polymerase, the error rate is approximately 1 error in 1,000,000,000 base pairings