THE CONTROL OF GENE EXPRESSION

GENE EXPRESSION – THE OVERALL PROCESS BY WHICH GENETIC INFORMATION FLOWS FROM GENES TO PROTEINS PROKARYOTES ARE BEST TO STUDY FOR THIS TOPIC…WHY?? THE LAC OPERON IN PROKARYOTES GIVES US A BETTER UNDERSTANDING OF HOW GENES ARE EXPRESSED

THE CONTROL OF GENE EXPRESSION THE LAC OPERON

THE CONTROL OF GENE EXPRESSION THE LAC OPERON – PRESENT IN E. COLI – ONLY FUNCTIONAL (TURNED ON) WHEN LACTOSE IS ABUNDANT…ENVIRONMENTAL CONDITIONS CAN IMPACT GENE EXPRESSION!!! – PARTS OF THE OPERON OPERON PROMOTER OPERATOR REPRESSOR REGULATORY GENE

THE CONTROL OF GENE EXPRESSION THE LAC OPERON – HOW DOES IT WORK?!?!

THE CONTROL OF GENE EXPRESSION THE LAC OPERON IS NOT THE ONLY OPERON OTHER OPERON’S MAY ALSO USE REPRESSORS; BUT THEY ALSO MAY USE… – ACTIVATORS  ??

THE CONTROL OF GENE EXPRESSION RANDOM QUESTION…YOU STARTED OUT AS A SINGLE CELL, AND THAT CELL MULTIPLIED/DIVIDED INTO A TRILLION CELLS BY THE PROCESS OF MITOSIS; BUT IF MITOSIS MAKES AN EXACT COPY OF A CELL, HOW COME EVERY CELL IN YOUR BODY ISN’T EXACTLY THE SAME???

THE CONTROL OF GENE EXPRESSION ANSWER – EVERY CELL IN YOUR BODY HAS THE EXACT SAME DNA; HOWEVER, NOT EVERY CELL EXPRESSES THE SAME DNA!!! (THIS QUESTION IS ON THE REGENTS EVERY SINGLE YEAR) DIFFERENTIATION – THE PROCESS BY WHICH CELLS BECOME SPECIALIZED IN STRUCTURE AND FUNCTION – OCCURS BECAUSE ONLY CERTAIN GENES IN EACH PARTICULAR CELL ARE TURNED ON, WHILE OTHERS ARE TURNED OFF (HOW EXACTLY THIS HAPPENS IS UNKNOWN)

THE CONTROL OF GENE EXPRESSION DIFFERENTIATED CELLS RETAIN ALL GENETIC INFO – WHEN A CELL DIFFERENTIATES (BECOMES SPECIALIZED) IT DOESN’T LOSE DNA, JUST DOESN’T EXPRESS IT – EVIDENCE OF THIS: CLONES REGENERATION NUCLEAR TRANSPLANTATION WHAT EXACTLY ARE STEM CELLS??

THE CONTROL OF GENE EXPRESSION ATTEMPTING TO EXPLAIN THE PROCESS OF DIFFERENTATION LIES IN DISCOVERING HOW EUKARYOTIC CELLS CONTROL GENE EXPRESSION THIS IS DIFFICULT, BECAUSE EUKARYOTIC GENOMES ARE LARGE AND COMPLEX; BUT WE SHALL DO OUR BEST!!! (VICTORY WILL BE OURS!!)

THE CONTROL OF GENE EXPRESSION MECHANISMS OF REGULATION IN EUKARYOTIC GENES – DNA PACKING – X CHROMOSOME INACTIVATION – COMPLEX PROTEIN ASSEMBLIES – ALTERNATIVE RNA SPLICING – mRNA BREAKDOWN – TRANSLATION INITIATION – PROTEIN INACTIVATION – PROTEIN BREAKDOWN

THE CONTROL OF GENE EXPRESSION DNA PACKING – HISTONES  – NUCLEOSOME  – TIGHTLY PACKED DNA PROBABLY DON’T GET EXPRESSED – HISTONES MUST LOOSEN FOR RNA POLYMERASE TO BIND

THE CONTROL OF GENE EXPRESSION X CHROMOSOME INACTIVATION – ONE X CHROMOSOME IS TIGHTLY PACKED/COMPACTED AND SHUT OFF ENTIRELY – ONE X CHROMOSOME IS PICKED AT RANDOM FOR EACH CELL – TORTOISE SHELL CAT 

THE CONTROL OF GENE EXPRESSION COMPLEX PROTEIN ASSEMBLIES

THE CONTROL OF GENE EXPRESSION COMPLEX PROTEIN ASSEMBLIES – TRANSCRIPTION FACTORS (TF’S)  – ENHANCERS  – SILENCERS 

THE CONTROL OF GENE EXPRESSION ALTERNATIVE RNA SPLICING – AN ORGANISM CAN GET MORE THAN ONE TYPE OF POLYPEPTIDE FROM A SINGLE GENE

THE CONTROL OF GENE EXPRESSION BREAKDOWN OF mRNA – mRNA GETS DEGRADED AT DIFFERENT TIMES INITATION OF TRANSLATION – CONTROLLING WHEN TRANSLATION OCCURS PROTEIN ACTIVATION – PROTEIN MAY BE CREATED IN A NON-FUNCTIONAL STATE PROTEIN BREAKDOWN – PROTEINS GET DEGRADED/BROKEN DOWN AT DIFFERENT TIMES

THE CONTROL OF GENE EXPRESSION MULTIPLE MECHANISM REGULATE GENE EXPRESSION

THE CONTROL OF GENE EXPRESSION OTHER CONTROL MECHANISMS – HOMEOTIC GENES A MASTER CONTROL GENE THAT REGULATES A BATTERY (LONG LIST) OF OTHER GENES – SIGNAL-TRANSDUCTION PATHWAYS A SERIES OF MOLECULAR CHANGES THAT CONVERTS A SIGNAL ON A TARGET CELL’S SURFACE TO A SPECIFIC RESPONSE WITHIN THE CELL

THE CONTROL OF GENE EXPRESSION SIGNAL TRANSDUCTION PATHWAYS – TWO TYPES

THE CONTROL OF GENE EXPRESSION CANCER  – ALL INDIVIDUALS HAVE CANCER GENES WITHIN THEIR DNA (ONCOGENES) – THEY ARE NORMALLY CONTROLLED AND KEPT OFF; HOWEVER, MISTAKES CAN HAPPEN!!!

THE CONTROL OF GENE EXPRESSION CANCER – ONCOGENES – PROTO-ONCOGENES – TUMOR-SUPPRESOR GENES

THE CONTROL OF GENE EXPRESSION CANCER – DEVELOPS LATER IN LIFE, MOST OF THE TIME, BECAUSE IT TAKES AWHILE TO DEVELOP SINCE MULTIPLE MUTATIONS ARE NECESSARY

THE CONTROL OF GENE EXPRESSION CANCER – EXPOSURE TO CARCINOGENS INCREASES THE RISK OF DEVELOPING CANCER – CARCINOGEN  INCREASE THE RATE OF MUTATION IN CANCER CAUSING GENES, OR INCREASE THE RATE OF CELL DIVISION KNOW EXAMPLES??? WHAT CAN WE DO TO PREVENT CARCINOGEN EXPOSURE??

THE CONTROL OF GENE EXPRESSION THANKS SO MUCH MR. KRAUZ FOR TEACHING US ALL THIS COOL INFO ON GENES AND STUFF, BUT HOW THE HECK DID ANYONE FIND OUT ABOUT THIS STUFF? COME BACK TOMORROW AND I’LL TELL YOU ABOUT ALL THE COOL TOYS THAT SCIENTISTS GET TO PLAY WITH TO LEARN STUFF ABOUT GENES!!!