![Page 1: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/1.jpg)
DNA Structure & Replication
Chapter 5
![Page 2: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/2.jpg)
Discovery of DNA as genetic material
1869 a compound found in the nucleus1920’s the chemical components of nuclein
determined1930’s experiments on single celled algae
Experiment 1 stalk removed, and regrew, therefore the DNA can not be in the stalk
Experiment 2 foot remove, and did NOT regrow, therefore DNA must be in foot.
Foot contained nucleus, so nucleus must contain genetic material1
![Page 3: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/3.jpg)
Rosalind Franklin (1920-1958) :-X-ray diffraction photograph of the DNA double helix in 1951-determined DNA must be a corkstrew
![Page 4: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/4.jpg)
Watson and Crick• James Watson & Francis Crick
•Described DNA as a double helix in 1953
•Nobel Prize for Physiology in 1962
![Page 5: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/5.jpg)
DNA StructureDNA consists of two molecules that are arranged
into a ladder-like structure called a Double Helix.
A molecule of DNA is made up of millions of tiny subunits called Nucleotides.
Each nucleotide consists of:1. Phosphate group2. Pentose sugar3. Nitrogenous base
![Page 6: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/6.jpg)
Nucleotide
Phosphate
Pentose
Sugar
Nitrogenous
Base
![Page 7: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/7.jpg)
NucleotidesThe phosphate and sugar form the backbone
of the DNA molecule, whereas the bases form the “rungs”.
There are four types of nitrogenous bases.
![Page 8: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/8.jpg)
Nucleotides
A
Adenine
T
Thymine
G
Guanine
C
Cytosine
![Page 9: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/9.jpg)
NucleotidesEach base will only bond with one other
specific base.
Adenine (A)Thymine (T)
Cytosine (C)Guanine (G)
Form a base pair.
Form a base pair.
![Page 10: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/10.jpg)
“The Code of Life”
•Nitrogenous Bases
•Purines: Adenine & guanine Double-ringed
•Pyrimidines: Thymine & cytosine Single-ringed
Triple bonds
double bonds
![Page 11: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/11.jpg)
DNA StructureBecause of this complementary base pairing,
the order of the bases in one strand determines the order of the bases in the other strand.
![Page 12: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/12.jpg)
![Page 13: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/13.jpg)
Anti-Parallel Strands
![Page 14: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/14.jpg)
DNA STRUCTURE https://www.youtube.com/watch?v=qy8dk5iS1f0
![Page 15: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/15.jpg)
DNA SEMICONSERVATIVE REPLICATION• The process of copying a
double-stranded DNA molecule
• DNA strands are antiparallel and complementary
• Each strand serves as a template for the reproduction of the opposite strand
• one strand of the newly formed DNA molecule is “conserved” from the original parent strand.
![Page 16: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/16.jpg)
The process of DNA Semiconservative Replication Continued:
• The 2 nucleotide chains unwind and unzip from each other. • Each old chain base pairs with new
nucleotides forming 2 identical DNA molecules that are identical to the original DNA molecule.• The 2 old chains determine the sequence of
the new chains since we know A pairs with T and C pairs with G.
![Page 17: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/17.jpg)
DNA structure and Replication
https://www.youtube.com/watch?v=8kK2zwjRV0M
![Page 18: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/18.jpg)
http://www.sinauer.com/cooper/4e/animations0601.html
http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120076/micro04.swf::DNA Replication Fork
![Page 19: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/19.jpg)
BIOFACT
If extended a single human DNA molecule would be ~ 6 cm long, that
is 1000s times longer than the diameter of the nucleus. This chromosome and another 45 chromosomes can fit into the nucleus because of efficient
chromatin packing.
![Page 20: DNA Structure & Replication Chapter 5. Discovery of DNA as genetic material 1869 a compound found in the nucleus 1920’s the chemical components of nuclein](https://reader035.vdocument.in/reader035/viewer/2022062321/56649dbb5503460f94aac028/html5/thumbnails/20.jpg)
ANOTHER BIOFACT !!
If you arrange all of the DNA strands in your body end-to-end, their total length would stretch 2 x 1010 ......That is well over 100 times the
distance between the earth and the sun !!!!