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Genetics of Cancer. Signaling cell. Signaling molecule. Signal Transduction: Way in which a cell can respond to signals from its environment Results in a change in which genes are expressed (turned on). Plasma membrane. 1. Receptor protein. 2. 3. Target cell. Fig. 11-12. Relay
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Signaling cell Signaling molecule Signal Transduction: Way in which a cell can respond to signals from its environment Results in a change in which genes are expressed (turned on) Plasma membrane 1 Receptor protein 2 3 Target cell Fig. 11-12 Relay proteins Transcription factor (activated) 4 Nucleus DNA 5 Transcription mRNA New protein 6 Translation
Growth factor Receptor Target cell Hyperactive relay protein (product of ras oncogene) issues signals on its own Normal product of ras gene Relay proteins Fig. 11-20a Ras is an oncogene (cancer gene) the normal form of the gene is a proto-oncogene Oncogenes STIMULATE cell division Transcription factor (activated) DNA Nucleus Transcription Translation Protein that Stimulates cell division
Normal tumor-suppressor genes prohibit cell division Growth-inhibiting factor Receptor Relay proteins Nonfunctional transcription factor (product of faulty p53 tumor-suppressor gene) cannot trigger transcription Fig. 11-20b Transcription factor (activated) Normal product of p53 gene Transcription Translation Protein absent (cell division not inhibited) Protein that inhibits cell division
A tissue comprised of billions of cells heterozygous for BRCA1 or BRCA2 Both alleles of BRCA1 or both alleles of BRCA2 must be mutant for cancer to develop. Why would in follow a dominant inheritance pattern? Your (my) probability of winning the lottery is very small. The probability that someone will win it is very large.
One of the key tools in DNA technology is the restriction enzyme
Where do these restriction enzymes come from???? What is their natural function??? How can we use them??? https://www.dnalc.org/view/15255-Producing-human-insulin-using-recombinant-DNA-Walter-Gilbert.html https://www.dnalc.org/view/15476-Mechanism-of-Recombination-3D-animation-with-with-basic-narration.html
Use restriction enzymes to break DNA into manageable sized pieces that we can separate using the technique of gel electrophoresis
What can we tell from this? • It can be used to compare the DNA from different organisms • Used to detect disease alleles • Used to “match” DNA samples • Determine parentage • Crime scene forensics
Crime scene Suspect 1 Suspect 2 1 DNA isolated Fig. 12-11 DNA of selected markers amplified 2 Amplified DNA compared 3
Recombinant DNA • DNA from 2 sources combined • Can be used to clone genes • Used to produce a particular protein How is this recombinant DNA made?
GMOs • Research 3 GMOs • Type of organism • What is modified (what gene)? • What is the benefit • Your thoughts…