Integrating Concepts in
Biology
PowerPoint Slides for Chapter 1:
Heritable Material
1.4 How does DNA’s shape affect its function?
by A. Malcolm Campbell, Laurie J. Heyer, &
Christopher Paradise
Title Page
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Biology Learning Objectives
• Draw the structure of DNA showing the double helix
and base pairings.
• Demonstrate how DNA replication is
semiconservative.
• Evaluate experimental design and analyze data from
research on DNA as molecular information.
Bio-Math Exploration Learning Objectives
• Estimate the amount of DNA in a sample by finding
the area under a curve.
• Determine the number of generations that have passed
in a population of cells.
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Nucleotide Structures
You should be able to distinguish
deoxyribonucleic acid (DNA)
from ribonucleic acid (RNA),
Fig.1.9
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Nucleotide Structures
You should be able to distinguish
deoxyribonucleic acid (DNA)
from ribonucleic acid (RNA),
Fig. 1.9
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Nucleotide Structures
RNA
ATP
Fig. 1.9
DNA
dATP
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Nucleotide Structures
rotate
90°
dATP
2’ carbon
Fig. 1.9
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Nucleotide Structures
ATP or dATP?
Fig. 1.9
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Watson and Crick DNA Model
Fig. 1.10
from Watson and Crick, 1953
Watson and Crick DNA Model
Fig. 1.10
from Watson and Crick, 1953
Watson and Crick DNA Model
Fig. 1.10
from Watson and Crick, 1953
Watson and Crick DNA Model
Fig. 1.10
from Watson and Crick, 1953
Watson and Crick DNA Model
Can you spot their error?
Fig. 1.10
from Watson and Crick, 1953
Watson and Crick DNA Model
Can you spot their error?
Fig. 1.10
from Watson and Crick, 1953
Watson and Crick DNA Model
phosphate
should be anti-parallel strands
Fig. 1.10
from Watson and Crick, 1953
Chemical Bonds
Fig. 1.11
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Chemical Bonds
You should be able to match
these representations with
the appropriate chemical bonds.
Fig. 1.11
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Chemical Bonds
Fig. 1.11
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Chemical Bonds
Fig. 1.11
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Chemical Bonds
Match the chemical
representations with
the appropriate bonds.
Fig. 1.11
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Chemical Bonds
Fig. 1.11
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Chemical Bonds
Fig. 1.11
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Chemical Bonds
Describe the
general
rules for each
bond type
found in
biological
examples.
Fig. 1.11
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Chemical Bonds
Fig. 1.11
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
Chemical Bonds
(N or O) and H
bases (+) and acids (-)
any element, often
C – C, C – O,
C – N, C – H
Fig. 1.11
Copyright © 2015 by AM Campbell, LJ Heyer, CJ Paradise. All rights reserved.
X-ray Diffraction of DNA
Maurice Wilkins’ data
Fig. 1.12
Rosalind Franklin’s data
from Wilkins, et al., 1953 and from Franklin and Gosling, 1953.
X-ray Diffraction of DNA
Maurice Wilkins’ data
Fig. 1.12
Rosalind Franklin’s data
from Wilkins, et al., 1953 and from Franklin and Gosling, 1953.
Watson & Crick Base Pairs
Find their
mistake.
Fig. 1.13
modified from
Watson and Crick. 1953b
Watson & Crick Base Pairs
Find their
mistake.
Fig. 1.13
modified from
Watson and Crick. 1953b
Watson & Crick Base Pairs
missed H-bond
Fig. 1.13
modified from
Watson and Crick. 1953b
Watson & Crick Base Pairs
Fig. 1.13
too far for H-bond
modified from
Watson and Crick. 1953b
Watson & Crick Base Pairs
1
pyrimidines
1
Fig. 1.13
modified from
Watson and Crick. 1953b
Watson & Crick Base Pairs
1
2
purines
1
Fig. 1.13
2
modified from
Watson and Crick. 1953b
Always Three Rings Wide
1
1
Fig. 1.13
2
2
3
3
modified from
Watson and Crick. 1953b
3 Models of DNA Replication
Fig. 1.14
modified from Meselson and Stahl. 1958.
3 Models of DNA Replication
all old
DNA
What are the implications
for each model?
Fig. 1.14
modified from Meselson and Stahl. 1958.
3 Models
of
DNA
Replication
half old
semi-conservative
half new
Fig. 1.14
modified from Meselson and Stahl. 1958.
3 Models of DNA Replication
all old
conservative
all new
Fig. 1.14
modified from Meselson and Stahl. 1958.
3 Models of DNA Replication
all stands
half new
Fig. 1.14
mosaic
modified from Meselson and Stahl. 1958.
3 Models
of
DNA
Replication
half old
all old
semi-conservative
conservative
all new
half new
all stands
half new
Fig. 1.14
mosaic
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
low concentration
(low density)
Fig. 1.15A
high concentration of salt
(high density)
from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
they wanted the DNA to
appear about the same total
darkness at each time point
backgrounds
vary due to
different
photographic
exposure times
Fig. 1.15A
from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
0
Fig. 1.15A
evenly distributed DNA
from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
15
Fig. 1.15A
partially
equilibrated DNA
from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
36
43
Fig. 1.15A
fully equilibrated DNA
from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
density of normal
(light 14N) DNA
Fig. 1.15A
from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
mix DNA made of
14N (light)
and
15N (heavy)
centrifuge in
salt gradient
Fig. 1.15B
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
density of light
(14N) DNA
mix DNA made of
14N (light)
and
15N (heavy)
centrifuge in
salt gradient
density of heavy
(15N) DNA
Fig. 1.15B
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
(14N)
DNA
Fig. 1.15B & C
(15N)
DNA
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
quantifying
DNA in each band
(14N)
DNA
Fig. 1.15B & C
(15N)
DNA
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
experiment
performed twice
Fig. 1.16
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
experiment #1
Fig. 1.16
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
experiment #2
Fig. 1.16
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all cells (DNA)
grown in heavy 15N
Fig. 1.16
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
harvest cells (DNA)
at time zero
Fig. 1.16
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all cells (DNA)
switched to light 14N
Fig. 1.16
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
harvest cells (DNA) at
several time points
Fig. 1.16
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
separate new DNA
by salt gradient
Fig. 1.16
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
separate mixed DNA
by salt gradient
Fig. 1.17
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
DNA
centrifuged
43 hours
Fig. 1.17
0
all old/heavy
(15N)
time = 0
(in generations)
high salt density
on right side
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
quantify DNA
in band
high salt density
on right side
Fig. 1.17
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all 15N DNA
Fig. 1.17
half 15N, half 14N DNA
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all light
Fig. 1.17
all heavy
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all light
all heavy
DNA
replicated
once
half 15N, half 14N DNA
Fig. 1.17
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all light
all heavy
DNA replicates
at different times
Fig. 1.17
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
14N
15N
14N
15N
all 15N DNA
50% 15N DNA
what has
happened?
Fig. 1.17
1.9
all light
all heavy
DNA
replicated
~ twice
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
14N
15N
14N
15N
all 15N DNA
50% 15N DNA
what has
happened?
Fig. 1.17
1.9
all light
all heavy
DNA
replicated
~ twice
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all light
all heavy
all 15N DNA
0
50% 15N DNA
1.0
what has
happened?
Fig. 1.17
1.9
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all light
all heavy
all 15N DNA
0
50% 15N DNA
1.0
half DNA is
100% 14N
half DNA is
50% 14N 50% 15N
1.9
Fig. 1.17
modified from Meselson and Stahl. 1958.
3 Models
of
DNA
Replication
half old
all old
semi-conservative
conservative
all new
half new
all stands
half new
Fig. 1.14
mosaic
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all 15N DNA
0
50% 15N DNA
1.0
1.9
Fig. 1.17
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all 15N DNA
0
✓ data
50% 15N DNA
1.0
1.9
Fig. 1.17
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all 15N DNA
0
✓
50% 15N DNA
half DNA is
100% 14N
1.0
half DNA is
50% 14N 50% 15N
1.9
Fig. 1.17
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all 15N DNA
0
✓
50% 15N DNA
half DNA is
100% 14N
1.0
✓ data
half DNA is
50% 14N 50% 15N
1.9
Fig. 1.17
modified from Meselson and Stahl. 1958.
3 Models
of
DNA
Replication
half old
all old
semi-conservative
conservative
all new
half new
all stands
half new
Fig. 1.14
mosaic
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
4
0&2
0&4
Fig. 1.17
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
all light
all
heavy
4
0&2
0&4
Fig. 1.17
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
4
0&2
0&4
Fig. 1.17
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
percentage
14N mixed 15N
Fig. 1.17
87.5
12.5
0.0
40.0
40.0
20.0
0 = 1 copy
+2 = 4 copies
52.5
7.5
40.0
0 = 1 copy
+4 = 16 copies
4 = 16 copies
modified from Meselson and Stahl. 1958.
Meselson & Stahl Experiments
DNA is replicated in a
semiconservative
process
Fig. 1.17
modified from Meselson and Stahl. 1958.