(dna)deoxyribonucleic acid (dna) –stores info., copies itself –directs cell activities...
TRANSCRIPT
![Page 1: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/1.jpg)
![Page 2: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/2.jpg)
• Deoxyribonucleic acid (DNA) (DNA)
– Stores info., copies itself
– Directs cell activities– hereditary material passed from cell → cell
• Nucleic Acid – polymer; monomer = nucleotidenucleotide.
– two kinds: DNA and RNA. .
![Page 3: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/3.jpg)
Sections in a DNA mol. called genes.
Genes code for proteins; the hereditary info. in DNA tells cell how to make proteins
![Page 4: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/4.jpg)
• Nucleotide:
three components (CP: 230) (Hon: 197)– 5 C sugar – phosphate group – nitrogenous base
(4 kinds in DNA)
![Page 5: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/5.jpg)
• Nucleotide:
three components (CP: 230) (Hon: 197)– a 5-carbon sugar – a phosphate group – a nitrogenous base
(4 kinds in DNA)
![Page 6: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/6.jpg)
Four Kinds of Nitrogenous Bases • PyrimidinesPyrimidines - single ring - single ring
bases.bases.– Thymine and CytosineThymine and Cytosine
• PurinesPurines - double ring - double ring bases.bases.– Adenine and GuanineAdenine and Guanine
• Base pairsBase pairs ((also called also called nucleotide pairsnucleotide pairs) ) are formed when a are formed when a purinepurine bonds with a bonds with a pyrimidinepyrimidine
• A-T and C-G (always)A-T and C-G (always)
C
C
C
C
N
N
OO
OO
ThymineThymine
C
C
C
C
C
N
N
OO
N
CytosineCytosine
C
C
C
C
N
N
N
AdenineAdenine N
N
C
C
C
C
C
N
NOO
N
GuanineGuanine N
N
C
![Page 7: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/7.jpg)
DNA STRUCTURE• Shape is like twisted ladder.• Called a double helix -two
strands bonded together & twisted– The bases form the rungs
of the ladder • hydrogen bonds hold pairs
together; A-T, C-G
– Sugars and phosphates form sides of ladder.
![Page 8: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/8.jpg)
The carbons in the sugar are labeled
![Page 9: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/9.jpg)
DNA Animation
http://www.johnkyrk.com/DNAanatomy.html
http://207.207.4.198/pub/flash/24/menu.swf
![Page 10: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/10.jpg)
Packaging DNA• Eukaryotic DNA:
many levels of packaging:– Fundamental
unit is Nucleosome –
• DNA wound around proteins called histones.
• (CP. 139)
• (Hon 151)
![Page 11: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/11.jpg)
Nucleosome
![Page 12: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/12.jpg)
Nucleosomes• Nucleosomes
• Lowest DNA packaging level
• Can be thought of as a length of thread wound around a spool, the thread representing DNA and the spool being histone proteins.
![Page 13: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/13.jpg)
DNA - By The Numbers!DNA - By The Numbers!• Each cell has about
2 meters (6 ft) of DNA.• The average human has
60-75 trillion cells.• Avg human has enough
DNA to go from the Earth to the sun more than 400 times.
• DNA has a diameter of only 0.0000000002 meters (20Ǻ) [1Ǻ =10-10 m]
The earth is 150 billion metersor 93 million miles from
the sun.
![Page 14: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/14.jpg)
Karyotypes
• Normal human male karyotype (the total set of chrom. of an organism)
![Page 15: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/15.jpg)
Karyotypes
• Normal human female karyotype
![Page 16: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/16.jpg)
The History of DNA
• Gregor Mendel-1866
– Determined “Unit characters” were the method of passing on traits for inheritance
• Friedrich Meischer - 1868
– Studied nuclei of pus cells obtained from discarded surgical bandages
– Detected a phosphorus-containing substance that he named nuclein.
![Page 17: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/17.jpg)
• Frederick Griffith 1928 : Work with Bacteria– Found that DNA taken from a virulent
(disease-causing) strain of bacteria (Streptococcus pneumoniae)
– Transformed a non-virulent form of the bacterium into a virulent form.
![Page 18: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/18.jpg)
Oswald Avery, Colin MacLeod, and Maclyn McCarty 1943 Continued the study of “Transformation” principle
![Page 19: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/19.jpg)
Mendel Meischer Griffith
Avery McCartyMacLeod
![Page 20: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/20.jpg)
Transformation Of BacteriaTwo Strains Of Streptococcus
Smooth Strain w/Capsule(Virulent)
Rough Strain(Harmless)
Capsule
![Page 21: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/21.jpg)
Experimental
Transformation Of Bacteria -Griffith’s Experiment
Control
Control
Control
OUCH!
Rough
Smooth (virulent)
![Page 22: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/22.jpg)
The History of DNA• Alfred Hershey and Martha
Chase - 1952– radioactive isotope tracer
experiment
– bacterial virus (bacteriophage T2) infects a host cell ( bacterium Escherichia coli)
– found that T2 virus DNA, not its protein coat, enters the host cell
– genetic information for replication of the virus
![Page 23: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/23.jpg)
Using SUsing S3535Bacteria grown in normal non-radioactive media
T 2 grown in media containing S35 incorporate S35 into their proteins
Blending causes phage protein coat to fall off
T2 attach to bacteria and inject genetic material
Is protein the genetic material?
When centrifuged, phage protein coats remain in the supernatant while bacteria form a pellet.
The supernatant is radioactive, but the pellet is not.
Did protein enter the bacteria?
![Page 24: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/24.jpg)
Using P32Bacteria grown in normal non-radioactive media
T2 grown in P32 containing media incorporate P32 into their DNA
Blending causes phage protein coat to fall off
T2 attach to bacteria and inject genetic material
Is DNA the genetic material?
When centrifuged, phage protein coats remain in the supernatant while bacteria form a pellet
The pellet is radioactive, but the supernatant is not.
Did DNA enter the bacteria?
![Page 25: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/25.jpg)
The History of DNA Structure
• Erwin Chargaff- 1940 - “Chargaff’s rule”
– four bases may occur in varying proportions in DNA of different organisms
– # of A = # of T, w/ two hydrogen bonds
– = # of G and C are present w/ 3 hydrogen bonds
• Rosalind Franklin and Maurice Wilkins
– X-ray diffraction study concluded DNA fibers have two strands.
![Page 26: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/26.jpg)
The History of DNA Structure
James Watson and Francis Crick - University of Cambridge -1953
Worked on problem of making a DNA molecule model that was double stranded but also had the specific A - T and G - C base equivalencies Solution-double helical structure for DNA.
![Page 27: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/27.jpg)
Chargaff
Franklin
Wilkins
![Page 28: (DNA)Deoxyribonucleic acid (DNA) –Stores info., copies itself –Directs cell activities –hereditary material passed from cell → cell nucleotideNucleic](https://reader035.vdocuments.net/reader035/viewer/2022062404/551b92d1550346a10a8b5a51/html5/thumbnails/28.jpg)
Watson and Crick