Cellular Functions and Microbial Genetics (Pertaining to bacteria)GeneticsGregor Mendel – father of modern genetics- Traits come in alleles – spread ingametes, & when they cometogether get differentcharacteristics - Discovered 2 laws of inheritance - Different characteristics areinherited separately o Green color & shape - Discovered dominant and recessiveelements (Recognized pattern of genetics)o Start with pure white &purple o Produce 3 purple and onewhite o R & r o Can be carried along butnot seenAklaptonuria – mutation of specific enzyme that breaks down homogentinsic (producing red urine)Lack of protein ezyme is inherited Thought that protein was genetic elementStreptococcus pneumonia (Spanish flu) was studied – killed many people Actually died from superinfection- Showed that one strain (rough- nonvirulent)Injected into mice and it couldn’t survive, but mice would - Smooth (virulent) strain – mice would die - Live bacteria would kill, used heat killed (s) bacteria, mice live- Mixed rough strain and heat killed = killing miceProved that genetic information could be spread/ transferred(transformation)1944 (perfected): Repeated same experiment but instead of whole bacteria (heat-killed), took rough strain, took lysates of smooth strain - Treated with… and got live bacteria; only when DNase treatment inhibited transformation – DNA carried genetic informationAlready known (been around in 1800’s) - 4 bases: 2 purines (Adenine and Guanine) & 2 Pyrimidines (Thymine and Cytosine) - Attached to sugar (deoxy-ribose) - Triphosphate for each nucleotide (structural units of RNA/DNA)How does it carry genetic informationand how does it spread?- Took different types of DNA fromdifferent organisms and showedthat the amounts of bases werevarious, the amount of A & Twere always the same (as were C&G) o Adenine and Thymine –base pairs o C & G also o Phosphate – back bone(keeps strands together)o Make up DNA complexDNA Structure - X-ray crystallography on DNA - Maurice came up with best pictures of DNA (tocrack DNA) - Published (1953)o Showed structureo Specific pairing = possibly copyingmechanism o Separating strands, building up will get twostrands B form: most common formA form: structurally different, same base pairs Add salt, polyamines, etc. Z form (third type) - Bacteria have chromosomes- We have 23 o Ours are linear - Plasmids o Most common o Replicate independently of chromosome o Circular = no ends to build ono Can have 1000’s of plasmids - Eukaryotes have organelles with DNA - Bacteria have subdomains – different things arehappening o Glycolysis – membrane o Nucleoid – DNA is located, RNA is beingmade and ribosomes are close (proteinsynthesis machine) Center = action is- Don’t need cell division, can transfer to ‘sister’ cell (can spread quickly)- Carries VF o Ex: E.Coli is healthy but not with certain plasmidso Conjugation – mating bridge - Proteins regulate - One strandwill go to eachdaughter cell(radio-labeled)Mechanism:- DNaA binds toreplicationorigin (spec.DNAsequence) oEukaryotic–many(10,000’so Bacteria (1-5)- Open up strands - Helicase = blue arrow - Single strand binding proteins will keepit open (purple) – don’t base-pair backtogether- Primase (starts replication)o Leading strand – polymerase will build on - easyo Problem: DNA will add bases from 5’ to 3’ – fork will go from origin to finish  Other strand also has to build on – backwards (5’ to 3’)  Requires primase etc. Make small fragments, ligated together, continue all throughout chromosome (because route is discontinuous) - Termination: at origin o Polymerases fall off and have two copiesHow does DNA give rise to proteins?- Genes = coding for proteins Transcription – copying the geneticinformation into messenger RNA - Ribosomes are made ofribosomal RNA- Trafficking information fromthe DNA to ribosomePromoter region – upstream of genethat is going to be a protein - Has specific sequences recog. By transcription factors Sigma factors brings RNA polymerase (will make RNA) – bring down to right gene After binding, RNA polymerase switches from closed complex to open - unwouldVery regulated - some genes willbe made all time, some times Polymerase can start movingPolymerase can start moving and making RNA Copying = looks like upper strand (leading strand) RED: RNAKeeps reading on – until fallsoffOnce fork reaches certainstate, termination sequence(will make hairpin loop) andpolymerase can’t moveforth, stops and falls off - Most common Specific protein Gene middle – upstream (codedinto protein)Downstream – terminator RNA ready to become protein Translation – RNA  Protein - Starting mutations - Phage – virus that infects bacteria - Induced mutations – if you deleted/inserted 3 bases, would still get protein to be expressed (but 2 or 1) would not - 20 AA, 4 bases (can’t be responsible for one) - Long tail of uracil and put in system – indicated that it would make one specific AA - Must be Transfer RNA – expressed anti-codon (specific 3 base pair) could bind from transfer RNA – carries spec. AACodon - A sequence ofthree nucleotides whichtogether form a unit ofgenetic code in a DNA orRNA molecule.More than 20combinationsNot all AA have sameamount, some morecommonStarting codon - 1st AA - Methionine- Yellow:Termination: NoAA - Protein is doneRight side: 3-d, 2,d (left)Specific. Anti-codon loop 3 base pairs – complement codon Specific for AA (acceptor stem)20 AA Building blocks to make proteins Need peptide bonds Groups bind together (covalent peptide bond) Can build on mRNA has been made Comes out (close)Specific sequence: (RBS) –always the same in everygene so that ribosome canbind in the right place - 1 base off =completelydifferent AA,codon Initiation factors will bringin tRNA for methiaonine Purpe thing will be put ontop (place wherepolypeptide bonds areoccuring) 30s and 50s ribosomalcomponents - Beneficial – antibiotics will affect this but not ourstRNA (bottom is anticodon)will recognize sequencebased on mRNA sequencebased on base-perry andanti-codon 2 places: - P site - A site - Once get together - Big ribosomal unitwill put togetherand create peptidebond - Dissociation of AAfrom tRNA to thenext and tRNA fallsoff- Next one will bind to codon, get another --- moves along Many ribosomes on one RNA 3 different termination sequences TRNA’s are different – noAA Everything falls off, peptide dies There are