Warmup• What are the 4 levels of protein structure?• What are 2 reasons why proteins are important?• Factor 8 is a blood clotting protein that most hemophiliacs lack. How would you make and purify large quantities of factor 8?
Do you have the sameDNA in all of your cells? Yes! All cells from an organism has the same DNA.
How is it possible that we have different types of cells? (What makes these cells different?)
What makes these cells different?Hint: DNA Transcription RNA Translation Protein Proteins make cells look different. In different types of cells, some proteins are made and other proteins are not made, changing their phenotype.
What makes these cells different? DNA Transcription RNA Translation Protein (Gene) Genotype Phenotyp eGene On Protein/Phenotyp e Gene Off No Protein
How do cells control what protein is made and what protein is not made?Cells control the process gene expression (how proteinsare made from DNA ) by gene regulation (how somegenes get turned on and other genes get turned off).Gene regulation allows for cell differentiation (when cells onlyexpress certain proteins to help them perform a specific function). Protein Gene RegulatorInteractive: http://www.pbs.org/wgbh/nova/teachers/interactives/regulating-genes/index.html
The lac operon regulates genes by turningon the genes to digest lactose only whenthere is lactose around it.
Gene Regulation in EukaryotesGene regulation in eukaryotes is complex! It canoccur at different steps along the gene expressionprocess.
Regulation of DNA Packing When DNA is tightly wrapped in chromatin, RNA polymerase cannot bind to transcribe the gene. Ex: X chromosome inactivationOswald and Sisters!
Initiation of TranscriptionSimilar to how prokaryotes regulate transcription.- Has regulator genes that code for activator proteins (Turn on) and repressor proteins (Turn off) to bind operator- Usually one promoter and operator for each gene. (few operons)- Uses transcription factors to help RNA polymerase transcribe
RNA Processing and BreakdownAlternative splicing is when different exons are cut to formthe mRNA making different proteins from the same gene
Regulation of TranslationmRNA gets degraded before it is translated to aprotein
Protein Alteration and BreakdownProteins can be cut or degraded