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Genetics and Society PowerPoint revised from: hum.utah.edu/~bbenham/2510%20Spring%2008/class%203%20central%20dogma.ppt. Outline. What is a gene? Central dogma Replication (DNA makes DNA) Transcription (DNA makes RNA) Translation (RNA makes Protein). ?. http://giant-panda.com/. genes.
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Genetics and SocietyPowerPoint revised from: hum.utah.edu/~bbenham/2510%20Spring%2008/class%203%20central%20dogma.ppt
Outline • What is a gene? • Central dogma • Replication (DNA makes DNA) • Transcription (DNA makes RNA) • Translation (RNA makes Protein)
? http://giant-panda.com/
genes http://giant-panda.com/
What is a gene? A gene is a section of DNA (usually several 10,000’s of base pairs long) http://cmgm.stanford.edu/biochem201/Slides/Chromatin%20Structure/01%20Human%20Chromosome.JPG
A gene is a section of DNA gene chromosome
What is a gene? A gene makes a protein. A gene is a section of DNA (usually several 10,000’s of base pairs long) http://cmgm.stanford.edu/biochem201/Slides/Chromatin%20Structure/01%20Human%20Chromosome.JPG
Enzymes Enzymes are a type of protein (or RNA molecule) that speed up metabolic reactions in plants and animals. They are not permanently changed or destroyed when they do so.
The Central Dogma I called this idea the central dogma, for two reasons, I suspect. I had already used the obvious word hypothesis in the sequence hypothesis, and in addition I wanted to suggest that this new assumption was more central and more powerful. ... As it turned out, the use of the word dogma caused almost more trouble than it was worth.... Many years later Jacques Monod pointed out to me that I did not appear to understand the correct use of the word dogma, which is a belief that cannot be doubted. I did apprehend this in a vague sort of way but since I thought that all religious beliefs were without foundation, I used the word the way I myself thought about it, not as most of the world does, and simply applied it to a grand hypothesis that, however plausible, had little direct experimental support. -Francis Crick
Central Dogma: DNA Complementarity RNA Protein
Central Dogma DNA Replication RNA Protein
"It has not escaped our notice that the specific pairing that we have postulated immediately suggests a possible copying mechanism for the genetic material"
C C T A G A G G A G A C A T A C T T G C G C C G G A T C T C C T C T G T A T G A A C G C G G C C T A G A G G A G A C A T A C T T G C G C C G G A T C T C C T C T G T A T G A A C G C G G G G A T C T C C T C T G T A T G A A C G C G G C C T A G A G G A G A C A T A C T T G C G C C Complementarity allows DNA to be copied exactlyReplication
Central Dogma DNA Replication Transcription RNA Protein
C C T A G A G G A G A C A T A C T T G C G C C G G A T C T C C T C T G T A T G A A C G C G G C C T A G A G G A G A C A T A C T T G C G C C G G A T C T C C T C T G T A T G A A C G C G G RNA C C U A G A G G A G A C A U A C U U G C G C C RNA is copied from 1 DNA strandTranscription DNA (Complementarity again)
C C T A G A G G A G A C A T A C T T G C G C C G G A T C T C C T C T G T A T G A A C G C G G C C T A G A G G A G A C A T A C T T G C G C C G G A T C T C C T C T G T A T G A A C G C G G RNA C C U A G A G G A G A C A U A C U U G C G C C RNA is copied from 1 DNA strandTranscription DNA (mRNA- messenger)
RNA vs. DNA http://www.mun.ca/biology/scarr/Ribose_sugar.html
RNA uses U in place of T About 1/10,000,000 C bases decompose to U per day. Because DNA uses T, not U, the cell automatically assumes that U is the result of a C gone bad and removes all U bases from DNA. C U T
Central Dogma DNA Replication Transcription RNA Translation Protein
Protein is the final product of the information Translation Protein mRNA
Proteins are long chains of amino acids Protein (a real protein would have hundreds of amino acids)
Protein chains fold into complex shapes that depend on the sequence of amino acids Hemoglobin Proteins are long chains of amino acids Protein
An RNA “adapter” is used to convert RNA to Protein Amino Acid tRNA U A C
Amino Acids tRNA U A C U C U C C U C U G U A U G A A C G C A U G A G A G G A G A C A U A C U U G C G U G A Complementarity is used to convert the information in RNA into protein mRNA
G A A U A C U C U C C U C U G U A U C G C A U G A G A G G A G A C A U A C U U G C G U G A Complementarity is used to convert the information in RNA into protein Protein mRNA
G A A U A C U C U C C U C U G U A U C G C A U G A G A G G A G A C A U A C U U G C G U G A AUG is the translation startUAA UAG or UGA are stop Protein mRNA START STOP
Where do these events occur in the cell? Nucleus Replication Protein mRNA mRNA Transcription Translation
RNA Not all of the DNA gets copied into RNA A gene is a piece of DNA that makes a protein DNA
Not all of the DNA gets copied into RNA A gene is a piece of DNA that makes a protein DNA RNA promoter • Some of the DNA encodes when, where and how much of the RNA to make. This is called the promoter.
Different cells copy different parts of the DNA into RNA Hemoglobin Insulin
Different cells copy different parts of the DNA into RNA Blood cell Hemoglobin mRNA hemoglobin Insulin
Different cells copy different parts of the DNA into RNA Pancreas cell Hemoglobin Insulin mRNA insulin
Genes in some well known organisms http://www.genomenewsnetwork.org/articles/12_03/yeast_screen.shtml http://elegans.swmed.edu/ ~1 mm 97 M base pairs 19,100 genes <10 m 12 M base pairs 6,300 genes http://www.ornl.gov/sci/techresources/Human_Genome/faq/compgen.shtml#genomesize
Genes in some well known organisms ~1 cm 180 M base pairs 13,600 genes ~10 cm 125 M base pairs 25,500 genes http://www.rhone-alpes-genopole.com/index.php?pageID=52&tabNum=2 http://www.cofc.edu/~bernardoj/Genetics%20Lab/212Lhome.htm http://www.ornl.gov/sci/techresources/Human_Genome/faq/compgen.shtml#genomesize
Genes in some well known organisms 2,500 M base pairs ~30,00 genes 2,900 M (~3 billion) base pairs ~30,000 genes http://www.bcgsc.ca/gc/mouse/ http://www.thatsweird.net/picture32.shtml http://www.ornl.gov/sci/techresources/Human_Genome/faq/compgen.shtml#genomesize
DNA RNA Protein http://giant-panda.com/ The exact types and amounts of protein made by our DNA make us what we are.
Identical twins share the same DNA http://english.pravda.ru/news/world/10-07-2006/83163-poland-0 Lech and Jaroslaw Kaczynski, president and prime minister of Poland
Genes provide possibilities • Hemoglobin genes make it possible to have normal blood • A large number of genes make it possible to have a properly wired brain.
Genes provide possibilities Can you name other examples of things that are possible or not possible because of genes?
Genes provide probabilities • A particular set of genes will make it probable that someone will be tall. • DNA repair genes make it probable that a person will not get cancer. Environment will affect the odds
Genes provide probabilities Can you name other traits that are affected by both genes and the environment?