Genetics Replication Transcription and Translation Replication and Transcription are processes that involve DNA directly Translation is via RNA DNA Double helix or two strands of different nucleotide sequences joined by hydrogen bonds Made up of the bases guanine thymine adenine and cytosine pairing C G A T Types of RNA RNA is made of up the bases Guanine uracil adenine and o Replicates antiparallel cytosine pairing C G A U o rRNA ribosomal RNA o tRNA transfer RNA o mRNA messenger RNA Their message is translated into proteins or at least a polypeptide Replication DNA is unzipped and is replicated in an antiparapllel fashion by DNA polymerase creating two strands of DNA Transcription Same thing but two new strands of RNA are formed instead Translation mRNA is taken to be synthesized into proteins First it s fed into rRNA then chunks of tRNA specific to each codon come along to be activated into making an amino acid o direct from notes Transcription and replication are the direct processes in which DNA participates DNA only indirectly participates in translation The message in message RNA mRNA is translated into an amino acid sequence which will eventually make up a protein Every three bases in mRNA codon has a complementary triad of bases in the transfer RNA anticodon o A thing unique to prokaryotes we do transcription in the nuclei and translation in the cytoplasm Prokaryotes do the whole sha bang in the cytoplasm And they re done simultaneously Genetic Change Mutation Transduction and Transformation Mutation changes to the DNA base sequence There are spontaneous mutations that occur naturally induced mutations caused by a chemical or physical agent and silent mutations where the genotype but not the phenotype is affected o Missense mutation The DNA base changes so the mRNA codon and consequently the tRNA anticodon and the resulting amino acid ends up different o Nonsense mutation the change in the DNA base codes for a premature stop codon in the amino acid sequence This stops translation altogether o Frameshift mutation the deletion of a DNA base which changes every codon beyond it This could be very serious if it occurs earlier in the message Insertion of a base is also a frameshift mutation o Mutation caused by ultraviolet radiation that results in no change in amino acid sequence would be called an induced silent mutation Thymine Dimers example of a physical mutagenic agent The creation of a thymine dimer caused by ultraviolet light Causes two adjacent thymines to bond with eachother which fucks up the transcription process which just fills in two bases by guessing o The repair process for thymine dimers takes two minutes via endonuclease cutting out the fucked up DNA o Caffeine interferes with thymine dimer repair Smoking example of a chemical mutagenic agent Erectile dyfunction and wrinkles Every young man woman s worst fear Smoking mutates in two steps o Inducer function the chemical inducer will mutate your lung cells to potentially become cancerous o Promoter function the more potent function it will go to the already mutated cells and promote the mutation to the cells around it double mutation Transformation One way gene transfer Does not occur in all bacteria Only a handful do this naturally We induce some to do this artificially in lab settings o Streptococcus pneumonia encapsulated bacteria injected into mouse mouse dies Take samples from dead mouse and find colonies of encapsulated bacteria But if you inject another with a nonencapsulated bacteria and he s fine If you inject dead encapsulated bacteria into a mouse he s also fine But if you inject the mouse with living nonencapsulated and some dead encapsulated bacteria the mouse dies You ll find colonies of living encapsulated bacteria in the dead mouse o What is happening The dead encapsulated guys released naked DNA that got taken up by the living and synthesized so that they could produces capsules as well o So transformation always requires a dead donor cell NOT a virus of any kind or a dead recipient cell Conjugation is another way to have one way gene transfer This is essentially bacteria sex except reproduction is not the goal of this kind of sex o Example of bacteria conjugation E Coli can do this but not every bacteria can F cells develops a sex pilus that attaches to an F cell which pulls her into physical contact with him and they form a mating bridge The F factor is coded into a plasmid that the guy sends across the mating bridge making the F cell into an F cell just like him THIS IS A GRAM NEGATIVE PROCESS o Gram positive example streptococcus strand without plasmid Z produces a pheromone called CIA that attracts a strand with plasmid Z or the recipient cell The guy with plasmid Z gets stuck to the guy without and transfers the plasmid that way No pili involved Transduction Phage attaches to donor bacterial cell and injects its viral DNA Phage DNA and proteins are produced and they break up some of the bacterial chromosomes into pieces Sometimes pieces of host cell DNA gets protein packaged up like any other new virus which can go and deliver DNA but cannot replicate So a new host cell integrates the old host cell s accidentally packaged DNA So we are relying on a mistake in DNA packaging Genetic engineering first messed around with in 1970 s Aided by the discovery of restriction enzymes o Restriction enzymes cut DNA They cut them in an staggered fashion making palindromic opposing sticky end Another chunk is cut at a point that is complimentary to the original sticky ends so they join together easily to make recombinant DNA o Generating these overlapping sticky ends on DNA is the function we use in genetic engineering Controls of Microorganisms in Lab Settings These are physical chemical and antimicrobial controls Sterilization the killing or removal of ALL organisms from a given area The methods of sterilization that will be discussed below are o Moist heat under pressure o Dry heat o Filtration o Ionizing Radiation o Incineration o Ethylene Oxide carboxide o Heat Physical controls including those that are not methods of sterilization incineration Moist heat under pressure autoclave Dry heat an oven Boiling water This is not a sterilizing control but a good go to Pasteurization combination of high temperatures over time Also not sterilizing Some of the earliest methods of pasteurization were targeting tuberculosis pathogens o Filtration membrane of a filter has holes too small to let microorganisms