1. DNA Structure and Replication Review!
Test - Multiple Choice, Matching, Short Answer

2. DeoxyriboNucleic Acid
What does DNA stand for?
DeoxyriboNucleic Acid

3. What is the sugar named in DNA?
DEOXYRIBOSE
5-Carbon sugar

4. In the DNA Double Helix, the sugar is bonded to what molecule?
Phosphate group

5. Follow up question – what is the bond that holds the sugar and phosphate together?!?
Covalent bonds

6. Phosphate and sugar are bonded together
Phosphate and sugar are bonded together. What is then bonded to the sugar molecule?
Nitrogenous Base

7. Name the 4 nitrogenous bases.
Adenine
Guanine
Cytosine
Thymine

8. The nitrogenous bases are bonded together by what type of bond
The nitrogenous bases are bonded together by what type of bond? This holds the 2 strands together.
Hydrogen bond

9. Tell me the difference.
Purine
Pyrimidine

10. Tell me the difference. Purine Adenine Guanine 2 Ring Structure
Pyrimidine
Thymine
Cytosine
1 Ring Structure

11. What nitrogenous bases pair together?
Adenine – Thymine
Guanine – Cytosine
Purine – Pyrimidines!!

12. This scientist used X-ray diffraction to find information about DNA
This scientist used X-ray diffraction to find information about DNA. Found that DNA is in the shape of a helix or a coiled spring.
Rosalind Franklin

13. James Watson & Francis Crick
DNA is in the shape of a double helix (twisted ladder). These Scientists realized that the double helix accounted for Franklin’s X-ray pattern, and it explained Chargaff’s rule of base pairing and how the 2 strands of DNA are held together. This 3D model can even tell us how DNA can function as a carrier of genetic information
James Watson & Francis Crick

14. Define Chargaff’s Rule
the amounts of adenine and thymine are almost always equal, as are the amounts of guanine and cytosine.

15. Fill in the chart! Adenine Thymine Guanine Cytosine
% of Each Base Pair
38%

16. Fill in the chart! Adenine Thymine Guanine Cytosine
% of Each Base Pair
12%
38%
Automatically you should know that Cytosine will be the same as Guanine.
38+38 = 76%
100-76= 24
Adenine and Thymine = 24 Total
24/2 = 12% each

17. Tell me the general steps of DNA Replication

18. 1
DNA Unwinds and Unzips
Helix unwinds and 2 DNA strands separate at the Hydrogen bonds between nitrogen bases 2
DNA Polyermase helps to link free floating DNA nucleotides with complimentary nucleotides on each of the two strands 3
Covalent bonds join nucleotides above and below each other on the new strands.
Hydrogen bonds join complimentary base pairs 4
Each new DNA MOLECULE formed contains One parent strand and a new strand

19. What ENZYME is present in the first step of DNA replication
DNA HELICASE!
HINT – THINK STRUCTURE – HELIX
(UNWIND & UNZIP)

20. What ENZYME is present to bring free nucleotides to the form the new strand of DNA .
DNA polymerase

21. What are the two strands referred to as in the process of Replication?
Parent Strand (original)
New Strand (copied)

22. What happens when an error is made in the replication process?
MUTATION

23. DONE!
Study
Note Packet
HW Packet
Feb Break Assignment