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56 Cards in this Set
- Front
- Back
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nucleic acids |
-RNA -DNA |
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DNA structure |
-is a polymer called a polynucleotide which is composed of nucleotide monomers |
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each nucleotide in DNA consist of a |
-nitrogenous base(Thyme, adenine, cytosine, guanine) -sugar deoxyribose -phosphate group |
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the phosphate of one nucleotide |
-is attached to the sugar of the next resulting in a sugar phosphate backbonefrom which the bases project |
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the polynucleotide strand has |
-directionality -from 5 'C end (with the phosphate group) to the 3'C end(with the -OH group) |
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each nitrogeneous base has a |
-chemical side group that can form hydrogen bonds with its appropriate partner -adenine -thymine -guanine -cytosine |
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adenine |
-can form two hydrogen bonds with thymine and only thymine -Complimentary base pairing |
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guanine |
-forms three hydrogen bonds with cytosine and only cytosine -complementary base pairing |
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result is |
-two DNA strands held together via hydrogen bonds between bases forming a double stranded polymer |
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polymer then |
-coils into helix so that the overall structure of DNA is a double stranded helix -one strand runs in the 3 to 5direction -the other runs 5 to 3 direction -strands held together by weak bonds (hydrogen bonds) the two strands are stable but can also be seperated when needed(such as during DNA replication) |
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the 2 functions of DNA |
-replication -directing protien synthesis |
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for cells to divide |
-it must be equipped with two identical copies of its DNA one for each new cell |
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crucial step for cell replication |
-DNa replication |
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DNA replication |
-the process of making a duplicate copy of the DNA -relies on the formation of new complementary sequencing by base pairing using existing strand as a template |
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steps involved in the DNA replication process |
-opening up the double helix -unravel the double helix -making primers -DNA polymerase builds the new strand -building the complement to the lagging strand -Removing RNA primers |
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opening up the double helix |
-replication begins at the origins of replication -proteins seperate into two strands of DNA to open up a buble in the double helix -each bubble has 2 Y-shaped regions called replication forcks -replication proceeds in both direction starting at the forks |
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unravel the double helix |
-helicase enzymes attach to replication forks and unzip the double helix |
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making primers |
-each existing strand can be used as templates for replication. -the enzymes that build th enew DNA strands cant attach directly to teh template -must attach to existing short RNA chains(primers) based paired with the template -the enzyme primase catalyzes the fomation of these primers -these primers allow for attachment of DNA polymerase III to the template strand |
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DNA polymerase buildds the new strand |
-DNA Polymerase III is the enzyme that synthesizes the complimentary strand of the DNA template -the polumerase III attaches to the primer then adds on more free nucleodtieds to the existing primer strand while catalyzing the covalent bonding of the new nucleotides -using complimentary base pairing th ecompliment to the template can b synthesized |
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building the complement to teh lagging strand |
-polymerase III can only add on new nucleotides in the 5 to 3 direction -on the 3 to 5 direction template the new complementary strand (leading strand) runs in 5 to 3 direction and polymerase III easily adds nucleotides -the laggin strand is manufatured in small fragments in the 5 to 3 direction called okazaki fragments -only one primer is needed in the leading strand each okazaki gragment on tehlaggidn strand requires its own primer |
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removing rna primers |
-rna primers are replaced with DNA by DNA polymerase I and the original template molecule has een successfully replicated -final step fragment sof hte DNA are ligated together by enzyme ligase |
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protein synthesis by DNA |
-central dogma of bio |
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central dogma |
-DNa codes for the synthesis of RNA(transcription) and RNA codes for the synthesis of protien (translation) |
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the specific dna sequence |
-dictates the sequence of the proteins which is responsible for the shape and function of the protien which affects the overall physical and physiological characteristics of an organism(phenotype) |
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genotype |
-specific DNA makeup of an organism -determines his or her phenotype(outward manifestation of genotype) |
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DNA->mRNA-> Protein-> phenotype |
ss |
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all human cells |
-except for egg and sperm -have 23 pairs of chromosomes - |
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chromosome |
-long molecule of DNA -may have hundreds of thousands of coding regions |
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coding regions |
-DNA sequences that code for productio of a protein -these function regions of DNa are our genes |
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DNA contains regions |
- that dont code for the production of protiens -noncoding regions of DNA have no known function but are highly variable from person to person |
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noncoding regions |
-of dna are hypervarialbe maning they may be used to id single individuals usiing molecular techs |
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PCR |
polymerase chain reaction |
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PCR |
-using with agarose gel elextrophoresis to analyze the DNA sampes from hypothetical crime scne |
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allele |
-variations of a gene -also be used to describe variations of noncoding regions |
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DNA profiling in csi thingy |
-use of molecular genetic methods to determine th genotype of a DNA sample |
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PCR |
-produces large amounts of a specific piece of DNA form trace amounts of starting material(template) -can be used to generate billions of copies of a desired DNa fragment -simple and specific -target adn amplify one spefcific segment of DNa a few hundred base pairs in length out of a complete genome of over 3 billion base pairs - all that is req for PCR is at least one DNA template strand , DNA polymerase, two dna primers, and four nucleotide building block subunits of DNA A, G, T and C, and reaction buffer |
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template |
-can be any form of double stranded DNA -only single template strand is needed to generate billions of new DNA molecules
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universal agreement |
-DNa sequences used for foresnic profiling are anonymous aka they come from the noncoding regions of our chromosomes that dont control any traits and have no function |
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loci |
-location on a chromosome sometimes called the genetic address -regions of the chromosomes with no traits and jucntions are found at specific ones of these |
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single locus |
-may have diff forms or types these diff forms are called alleles -may be bi-allelic having only two diff forms or may b polymorphic |
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Short Tandem Repeats |
-STRs -short DNA sequences that r repested in direct head to tail fashion -DNa sequences used in forsenic labs r noncoding regions that contain segments of this |
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polymerase chain reaction |
-Dna profiling is amp of the copies present in the small oamound of evidentiary DNA by this is how STR allleles r detected |
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allele ladder |
-Following gel electrophoresis which sepreates PCR products according to size the apttern of bands is compared to this to id the allels present in the original sample |
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Using PCR based analysis the sample will b examined at |
-13 diff genetic locations or loci -use comp to inerpret results |
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power of discrimination |
-is used in real crimes scene analysis -DNA profiling is performed as at many loci to imporove this |
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PCR allows |
-forensic specialist to specifically amplify or copy any region of hte DNA |
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BXP007 |
-is the locus that you willperform PCR analyis in the experiment -using tempalte DNAs obtained froma simulated cirme scene and victim |
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follwing PCR |
-run an agarose gel to seperate teh PCR products visualzie PCR products and compar them to a simultated latdder of possible alels for the locus and assign a genotype for thetemplates to see if any suspects genotypes match the scene |
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PCR amplification |
-is DNA replication ina test tube |
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target sequence |
-the portion of the DNa that ou wan tot cmake copies of |
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PCR relies on three principles of molecular bio |
-denaturation-sep doubl stranded dna template into single strands -95C -annealing-complementary dna strand hybridization vis dna primers-52C -extension -dna strand synthesis via dna polymeras-72C |
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thermal cycler |
-each step done by manipulating temp in a machine is called this - it exposes the dNA templete to three cycles of temp |
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taq(thermus aquaticus) polymerase |
-the thermostable DAN polymerase -enzyme was isolated from teh thermophicic bacterium, taq which lives in high temp tsteam vents |
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master mix |
-is req for PCR -contains componenets necesary for pcr to occur includigng the enze (taq DNA polymerase, indidbvidual building blocks of DNA(free nucleotides or dNTPs) asa special free buffer to maintian optimum pH and salts and MgC12 |
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Salts and magnesium ions |
-r called cofactors -included for th etaq polymerase to perform optimally |
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during this experiment |
-given master mix that compes prepared with all of the ingredients aboce but also the pimers |
