Exam 3: Concepts to Know - Part B

StudyBlue printing of Exam 3: Concepts to Know - Part B html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, font, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td { margin: 0; padding: 0; border: 0; outline: 0; font-size: 100%; background: transparent; } body { line-height: 1; } blockquote, q { quotes: none; } blockquote:before, blockquote:after, q:before, q:after { content: ''; content: none; } /* remember to define focus styles! */ :focus { outline: 0; } /* remember to highlight inserts somehow! */ ins { text-decoration: none; } del { text-decoration: line-through; } /* tables still need 'cellspacing="0"' in the markup */ table { border-collapse: collapse; border-spacing: 0; } /* end RESET */ .header { min-width:800px; } .logo { padding:6px 20px 2px 20px; margin:0; font-size:25px; font-weight:bold; color:#808285; position:relative; border-bottom: 1px solid #c5c5c5; } .logo-blue { color:#70adc4; } .logo-desc { font-weight:normal; font-size:19px; color:#cccccc; margin-top:50px; position:absolute; display: none; } .back-button { position:absolute; top:20px; right:20px; font-size:13px; line-height:25px; color:rgb(0,175,225); font-weight:normal; } .back-button a { color:rgb(0,175,225); } .instructions { padding:0; margin:0; width:100%; position:relative; color:rgb(100,100,100); } .step-holder { border-left:1px solid #ededed; margin-left:20px; } .steps { padding:15px 0; float:left; width:24%; border-right:1px solid #ededed; text-align:center; } .steps-01 { } .steps-02 { } .steps-03 { } .steps-04 { } .label { padding:5px 10px; } .print-button { } .print-button a { background-color:rgb(0,175,225); color:white; line-height: 19px; padding:9px 8px 5px 30px; font-size:14px; text-decoration:none; background-image: url(images/printer.png); background-repeat: no-repeat; background-position: 7px 50%; -moz-border-radius: 5px; -webkit-border-radius: 5px; } .print-button a:hover { background-color:black; } .theNote .content { width: 8.0in !important; margin: 5px auto; padding:20px; background-color:white; } .theNote .header { border-bottom: 1px dashed #C8C8C8; font-size: 17px; padding: 0 0 10px; line-height: 19px; color: #00ADE1; min-width:500px; } .theNote .body { font-size: 14px; line-height: 19px; padding: 10px 0; } .theNote{ padding:6px 0; clear:both; background-color: rgb(200,200,200); } .theNote h3{ color: rgb(100,100,100); } .theNote h1, .theNote h3{ background-color:white; padding:2px 20px; width:8.0in !important; margin: 0 auto; font-size: 15px; } .theNote h1{ padding-top: 10px; font-size: 15px; } .theNote h1:first-child{ font-size: 20px; } .theNote h3 { font-size: 14px; font-weight: normal; } #options { border: 3px double #ccc; padding: 5px 12px; margin: 10px 50px 10px 20px; float: left; } #info { border-top: 1px solid #ccc; padding-top: 5px; font-style: italic; } li { margin: 5px 10px 5px 25px; } ul li { list-style: disc; } ol li { list-style: decimal; } img { border: 0; } table { clear: both; width: 100%; border: 1px solid #c5c5c5; border-width: 1px 0; margin: 0; page-break-after: always; } table#page { page-break-after: auto; } td { text-align: center; font-size: 12px; border-bottom: 1px dashed #c5c5c5; height: 1.75in; width: 50%; padding-left: 15px; } .leftside { border-right: 1px solid #cccccc; padding: 0 15px 0 0; } .bottom td { border-bottom: none; } .clearfix { clear:both; line-height:1px; height:1px; } img { max-width:80%; max-height:150px; margin:20px; } @media print {.header { display: none; } .content .header{ display:inherit; } table { border: 1px dashed #bbb; border-width: 1px 0; } .theNote{ background-color:white; } } Protein Synthesis: Transcription & Translation All types of RNA are formed through transcription of DNA: but only mRNA is translated into protein. Transcription (copying) - RNA Polymerase converts template strand of DNA into mRNA. Initiation - RNA polymerase finds promoter region on template strand. (TAC on the DNA) codes for AUG on mRNA Elongation - RNA polymerase adds complimentary bases to 3' end Termination - 3 stop codons (redundancy) cause RNA polymerase to fall off Translation - Occurs in ribosomes where complimentary tRNA is brought in with AA's Initiation - ribosome scans mRNA for start codon (AUG) Elongation - tRNAs enter loaded with AA; fills P-site first, then A-site Termination - Protein Folding - Protein Processing - Process : triplets of Template Strand DNA --> mRNA codons --> tRNA anticodons --> Amino Acids --> Protein. Prokaryote - both occur simultaneously in the cytoplasm; one code = multiple proteins Eukaryote - transcription occurs independently in the nucleus and translation occurs in the cytoplasm; one code = 1 protein Players : RNA Polymerase - catalyzes entire process mRNA - carries DNA sequence tRNA - translates message rRNA - forms ribosome and H-bonds to mRNA as translating occurs Primer - RNA that begins DNA replication Ribosome - the catalyst that binds mRNA and tRNA together Regulation Eukaryotic Introns and Exons allow for variation and expression - not all introns are useless. Operons - regulator gene makes a repressor that acts on the promotor/operator site of the gene Inducible - Lactose Operon is switched OFF by default: Repressor is locked to the operater, preventing transcription; substrate/lactose attaches to repressor, causing it to fall off and transcription begins. Repressible - Operon is switched ON by default: Repressor is inactive, so transcription occurs; if substrate concenration increases, it attaches to repressor, causing it to bind to the promotor/operator site and halting transcription. Mutations Spontaneous – random change Induced – chemical, radiation. Point – change a single base Nonsense – change a normal codon into a stop codon Back-mutation – mutation is reversed Frameshift – reading frame of the mRNA changes Transmission of Genetic Material Conjugation - genetic transmission through direct contact between cells. Transfer of plasmid DNA from a F + (F factor) cell to a F - cell An F + bacterium possesses a pilus Pilus attaches to the recipient cell and creates pore for the transfer DNA High frequency recombination (Hfr) donors contain the F factor in the chromosome Transformation - DNA released from a killed cell can be accepted by a live competent cell, expressing a new phenotype as in Griffith's experiment on mice and Streptococcus pheumonieae . Nonspecific acceptance of free DNA by the cell (ex. DNA fragments, plasmids) DNA can be inserted into the chromosome Competent cells readily accept DNA Transduction - Bacteriophage infect host cells Serve as the carrier of DNA from a donor cell to a recipient cell Generalized - accidental tranfer via bacteriophage Specialized - prophage includes host DNA and subsequent infection combines DNA Transposon “Jumping genes” Exist in plasmids and chromosomes Contains genes that encode for enzymes that remove and reintegrate the transposon Small transposons are called insertion elements Antimicrobial targets: Block cell wall synthesis/production: peniciliins and cephalosporins Disrupt cell membranes: polymixins - antifungal Block protein synthesis: Tetracycline, chloramphenicol, erythromycin Block nucleic acid synthesis: quinolones, flouroquinolones Inhibit folic acid synthesis: sulfonimides, trimethoprim, sulfones Characteristics of ideal antimicrobial Rx Selective - still has AE's but mild ie: stomach upset. - cidal - not -static. Soluble . Active long enough - needs to get beyond liver so we make slow release, etc to overcompensate. Bring count low enough to enable immune system time to rev up and act; this is to compliment/assist defenses but not replace them. Needs to penetrate stomach and into blood stream. Site of delivery. Don't disrupt other systems of host. Narrow - targets specific Genus vs. Broad spectrum - can induce selective pressure for resistance. Antimicrobial classes, effectiveness, applications, examples: Halogens - Chlorohexidine - Isopropyl/ethyl Alcohol - H 2 O 2 - Soaps - Heavy Metals -