Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria...
-
Upload
clementine-garrison -
Category
Documents
-
view
224 -
download
4
Transcript of Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria...
![Page 1: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/1.jpg)
Chapter 13: DNA
![Page 2: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/2.jpg)
I. Mystery of DNA Structure
A. Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth bacteria and they live. Inject mice with heat-killed rough and they live. Mix heat-killed rough with healthy smooth, mice
die. Conclusion: Transforming factor smaller than
cell.
![Page 3: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/3.jpg)
I. Mystery of DNA Structure
B. Hershey/Chase (1950s)
Radiolabeled proteins and DNA.
Found viruses injected radiolabeled DNA,
but no proteins.
Conclusion: DNA is transforming factor.
![Page 4: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/4.jpg)
Figure 16.2a The Hershey-Chase experiment: phages
![Page 5: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/5.jpg)
Fig. 13.5, p. 217
virus particle labeled with 35S
virus particle labeled with 32P
bacterial cell (cutaway view)
label outside cell
label inside cell
![Page 6: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/6.jpg)
I. Mystery of DNA Structure
C. Chargaff (1950s): Worked with DNA and found that the amount of adenine (A) equaled the amount of thymine (T) while the amount of cytosine (C ) equaled the amount of guanine (G). Conclusion: Chargaff’s base-pairing
rule.
![Page 7: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/7.jpg)
I. Mystery of DNA Structure
D. Franklin/Wilkins (1953): X-ray
crystalography
They froze DNA and ran x-rays through
resulting crystal.
Conclusion: DNA tightly-wound helix
(at least they provided the evidence
for this conclusion).
![Page 8: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/8.jpg)
Figure 16.4 Rosalind Franklin and her X-ray diffraction photo of DNA
![Page 9: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/9.jpg)
I. Mystery of DNA Structure
E. Watson & Crick (1953):
Assemble all evidence and correctly
interpret data to create double helix.
Conclusion: Current model of DNA
(and Noble prize and fame and
glory and chicks)
![Page 10: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/10.jpg)
II. Model of DNA
A. Nucleotide: Basic building block of DNA.
1 phosphate group, 1 deoxyribose
sugar, 1 nitrogenous base.
![Page 11: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/11.jpg)
II. Model of DNA
A. Nucleotide:
1. Sugar (Deoxyribose): Each carbon is
numbered sequentially.
![Page 12: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/12.jpg)
Fig. 13.7, p. 219
2-nanometer diameter, overall
distance between each pairof bases = 0.34 nanometer
each full twist of the DNA double helix = 3.4 nanometers
![Page 13: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/13.jpg)
A. Nucleotide
2. Phosphate: Negative yet next to each other along DNA backbone, resulting in twisting.
![Page 14: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/14.jpg)
II. Model of DNA
A. Nucleotide:
3. Nitrogenous Bases:
Adenine and Guanine are Purines
(double ring structures)
Cytosine and Thymine are
Pyrimadines (sing ring structures)
![Page 15: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/15.jpg)
Fig. 13.6, p. 218
phosphate group
sugar (ribose)
ADENINE (A)
base with a double-ring
structure
THYMINE (T)
base with a single-ring structure
CYTOSINE (C)
base with a single-ring structure
GUANINE (G)
base with a double-ring
structure
![Page 16: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/16.jpg)
II. Model of DNA
B. Bonds within DNA Molecule
1. Phosphate to Sugar: Covalent (note which carbon in sugar is attached to which phosphate).
![Page 17: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/17.jpg)
II. Model of DNA
B. Bonds within DNA Molecule
2. Sugar to Nitrogenous Base: Covalent.
3. N-base to N-base:
Hydrogen Bonds.
![Page 18: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/18.jpg)
II. Model of DNA
C. Complete molecule is
‘antiparallel’ (one side
runs 3’ to 5’, other side
runs upside down,
or 5’ to 3’)
![Page 19: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/19.jpg)
wx C
in-text, p. 219
For each, 1. How many base pairs?
2. How many nucleotides?
3. How many sugars?
4. Circle a hydrogen bond.
![Page 20: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/20.jpg)
III. DNA Replication
A. Replication: Occurs in the nucleus; process of DNA creating an exact replica of original strand.
![Page 21: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/21.jpg)
III. DNA Replication
B. Semi-Conservative Nature of Replication
The two daughter strands are half new and half original (order and molecules of parent strand are conserved ).
Each half of original strand becomes a template for each new DNA molecule. The new strand is half old, half new.
![Page 22: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/22.jpg)
III. DNA Replication
C. Steps of Replication: 1. DNA uncoils and unzips (done by enzyme DNA helicase). 2. New nucleotides are added to exposed strand and added by DNA polymerase enzyme. 3. DNA ligase fills in gaps in new DNA strands.
![Page 23: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/23.jpg)
III. DNA Replication
D. Okazawi Segements: DNA is read from 3’ to 5’.
1. Leading strand reads 3’ to 5’ as DNA is
unzipped.
2. Lag strand would have to wait for entire
strand of DNA to unzip to begin; rather
it builds short segments, known as
Okazawi segments (later ‘stitched’
together with DNA ligase).
![Page 24: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/24.jpg)
Note 3’ to 5’ direction:
![Page 25: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/25.jpg)
Figure 16.13 Synthesis of leading and lagging strands during DNA replication
![Page 26: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/26.jpg)
Label Middle image 3’ to 5’
![Page 27: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/27.jpg)
Okazaki Segment Illustrated
![Page 28: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/28.jpg)
III. DNA Replication
E. Replication Fork/Bubble:
As DNA unzips, it replication begins
immediately. Replication simultanelously
occurs at many sites along a strand of
DNA.
![Page 29: Chapter 13: DNA. I. Mystery of DNA Structure A.Griffith (1920s): Injected mice with deadly bacteria (rough colony) and they die. Inject mice with smooth.](https://reader030.fdocuments.net/reader030/viewer/2022032706/56649ef55503460f94c08605/html5/thumbnails/29.jpg)
Figure 16.10 Origins of replication in eukaryotes