Preview Bellringer Key Ideas DNA: The Genetic Material Searching for the Genetic Material The Shape of DNA The Information in DNA Discovering DNA’s Structure Summary. Section 1: The Structure of DNA. Read each question, and answer based upon what you learn in the section.
1. With what kinds of bacteria did Griffith inject mice?
2. What was different about the S bacteria and the R bacteria?
3. Why were the heat-killed S bacteria harmless?
4. Why was the mixture of heat-killed S bacteria and R bacteria virulent?
5. What did Griffith discover as a result of his experiments?
6. How did Avery discover that the material responsible for transformation in bacteria was DNA?
7. Viruses that infect bacteria are called [bacteriophages / rough].
8. A virus is made of DNA and [proteins / cell walls].
9. Radioactive sulfur was used to label the [DNA / protein] in the viruses.
10. Radioactive phosphorus was used to label the [DNA / protein] in the viruses.
11. Hershey and Chase discovered that after the 32P-labeled phages infected the bacteria, most of the radioactive phosphorus was found in the layer containing [bacteria / phage].
Match the letter of the phrase with the appropriate term
_____ 12. double helix
_____ 13. nucleotides
_____ 14. deoxyribose
_____ 15. hydrogen bond
_____ 16. nitrogenous bases
_____ 17. adenine
_____ 18. cytosine
_____ 19. Chargaff
Explain how the terms in each pair are related to each other.
20. base-pairing rules, complementary
21.Wilkins and Franklin, DNA structure
a. a five-carbon sugar
b. type of weak bond between base pairs that holds the double helix together
c. four kinds and they form specific pairs
d. subunits that make up DNA
e. one of two pyrimidines used as a nitrogenous base in nucleotides
f. one of two purines used as a nitrogenous base in nucleotides
g. discovered that the amount of adenine always equaled the amount of cytosine and that guanine always equaled cytosine
h. two strands of nucleotides twisted around each otherDR 13.1. Section: The Structure of DNA
How is the structure of DNA similar to that of a ladder or spiral staircase?
How is it different from that of a ladder or spiral staircase?
DNA is often compared to a ladder or a spiral staircase. Look at picture to the right and answer the following questions.
Harmless bacteria cause pneumonia in mice.
Deadly bacteria that was made harmless because it was boiled to death.
Harmless bacteria mixed with killed deadly bacteria…Griffith’s Discovery of Transformation
Conclusion… Whatever made the deadly bacteria deadly was being transferred into the harmless bacteria. This process of exchanging information between organisms is called TRANSFORMATION…
The Structure of DNA other.
Compliments… not mirror images
Hydrogen BondsDNA: Hydrogen Bonding
Hydrogen BondThe Bases
The “puzzle piece” refers to the hydrogen bonding between the paired bases.
Guanine and cytosine have 3 hydrogen bonds
whereas thymine and adenine have 2 hydrogen bonds.Complimentary Bases
Look at the number of rings then the number of bonds…
Ribose the genetic material.