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Unformatted text preview: ith these observations, we preoperatively
diagnosed the tumor to be a ovary mature cystic teratoma of the “Homunculus” Qvarian X-ray Ovarian X-ray teeth Mass removed Teratoma, beyond the teeth and hair
normally found within them, this one has a small arm
that retains the grasping reflex: Fig. 18-18a Eye Antenna Wild type Fig. 18-18b Leg Mutant What turns genes on/off? Experiments with alternate fuel
sources E.coli + glucose = glucose breakdown
enzymes present ) E.coli + glucose & lactose = only glucose
breakdown enzymes present )
CONCLUSION: E.coli has the genes that code
for glucose breakdown enzymes
but NOT for lactose breakdown
enzymes glucose O glycolysis enzymes Lactose E.coli + lactose only
Lactose breakdown enzymes produced
E.coli does have the genes that code for
Lactose breakdown enzymes……..
…THEY ARE TURNED OFF! Jacob & Monod –1961
“Lactose Operon” an inducible operon under negative “i” gene regulator structural enzymes control a
degradative pathway Lac Operon Lac Operon w glucose & no lactose Glucose & no lactose Lactose present & no glucose Lactose inactivates repressor
“derepression” Experiments with alterna...
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- Fall '12