Genetics Test 2 Auburn
Genetics Test 2 Auburn BIOL 3000 - 002
Popular in Genetics
Popular in Biology
This 10 page Class Notes was uploaded by Lauren Smith on Sunday September 20, 2015. The Class Notes belongs to BIOL 3000 - 002 at DCH Regional Medical Center taught by Michael C. Wooten in Fall 2015. Since its upload, it has received 45 views. For similar materials see Genetics in Biology at DCH Regional Medical Center.
Reviews for Genetics Test 2 Auburn
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/20/15
92015 1020 PM 91 1 Friday Karyotyping the study of chromosomes 0 Karyotyping does not mean the same thing as idiogram o Idiogram the alignment of chromosomes based on shape and size 0 Each chromosome has a centromere there are four basic types 0 1 Metacentric the centromere is located in the middle so that the centromere has arms of equal length 0 2 Submetacentric the centromere is displaced toward one end so that one arm is long and the other is short 0 3 Acrocentric the centromere is near one end so that there is a long arm and a knobsatellite at the other end 0 4 Telocentric the centromere is at or very near to the end of the chromosome 0 By metaphase we have these highly compacted chromosomes common to have centromere at top which is common 0 If you stain these chromosomes during metaphase you can get a lot more information from them show up light and dark spots 0 DNA is actually really different in the two areas and the strips tell us that there are two types of compaction on chromosomes Heterochromatin darker areas because there is more packed DNA which holds more stain noncoding does not produce any proteins 0 remains a highly condensed section throughout cell cycle even during interphase 0 generally associated with the structures end of chromosomes are almost always dark bc they are slightly packed up telomere centromere has a lot of things going on right there also a dark area 0 Two types of Heterochromatin o Constitutive always dense at least 30nm fiber usually more even in 61 they are packed Noncoding regions centromeres and telomeres o Facultative can go in or out of being heterochromatin has potential to become a whole chromosome sometimes its really packed up sometimes it is not Barr Body take chromosome and pack it up so you cant use it then when you need it you just loosen it up 0 X inactivation whole chromosome is noncoding 0 Female xx has 1 Barr Body and male xy has no Barr Body 0 also important in calico cats have x inactivation inactive alleles on condensed chromosomes 0 Some stay dense throughout the cell cycle Euchromatin lighter area with less dense amount of DNA 0 Where our genes tend to be when not in metaphase because its more open 0 Remember his in class example 0 Packing a sleeping bag some areas you pack tighter than others Relationship of Genome Size to Species Complexity 0 Does the amount of DNA in a genome correlate with the complexity of the organism NO C value paradox C Value Paradox o c value concentration of DNA 0 we have more DNA than we need we still don t know what most of our DNA is o genome size DOES NOT correlate with organismal complexity 0 Two things closely related can have a difference of thousands of DNA 0 Does excess DNA have function 0 The onion test Gregory 2007 onion has 16 chromosomes and human has 46 onion has 5x more noncoding DNA isitjustjunk basic idea through evolution we don t have gills anymore but we still have the genes for it 0 recently we found out a lot of it does have function OOOO 0 DNA is double stranded so if we heat it up it becomes single stranded and when it cools off we can watch it come back together 0 Idea is that DNA will line up like it should with complementary bases if it happens quickly then there isn t as much DNA 0 can also have bumps on line created by different amounts of DNA Slow parts have a lot of DNA and fast parts have less DNA Cot Curve concentration over time o tells us the genome size 0 Three basic classes of Nucleotide Sequences for DNA HR MR U o 1 Highly Repetitive HR 0 not big enough to make proteinsgenes noncoding 0 little pieces of sequence that are just copied all over the genome 0 simple sequenceleast complex rapid reassociation o clustered around centromeres and telomeres 0 can be as short as two bases some of it is signaling sites for proteins and nucleosomes but in general it helps form chromosomes 0 Microsatellite Repeat Will use these genotypes in lab these repeats grow and shrink everytime you go through replication because they don t always line up perfectly called genotyping think CSI shows where they find hair etc o 2 Moderately Repetitive DNA Sequence MR 0 15 30 of our genome 0 found mainly in euchromatin 0 these are big pieces and can be copied thousands of times 0 Makes small proteins used in nucleus nuclear proteins this part of genome might be more important than anything else 0 3 Unique U 0 these are our classic genes Coding 0 used to think there was 100000 genes now we think there are about 20000 0 represents about 5 proteins that make you you o If we take max of HR MR and U we only have half of our DNA Don t know what the rest of our DNA is Organization of Genes Euchromatin 1 Solitary Unique 0 This is the gene for vast majority of those 20000 genes are solitary o Haploid single copy of a gene Diploid two copies of a gene 0 2 Duplicated 0 often have very distinct function version in muscle liver and eye do similar thingscode for similar polypeptides but have different genes they are just copies 0 Created because of unequal crossover during meiosis 3 Multigene Families 0 genes of related DNA sequences share functions and chromosomal location 0 qlobin qenes complex protein made of 4 parts need different hemoglobins for embryo fetus adult similar but slightly different genetics because they do slighlty different things 0 4 Pseudogenes o pseudi false fake genes 0 nonfunctional due to over substitution or deletions in nucleotide sequence 0 Super Gene Family Many genes associated with the same thing a Ex Mice can smell each other and tell who is within their family Gene tree on power point notes shows humans have turned off 15 of these 50 genes because we don t need GENES olfactory receptors like other animals do this way we don t waste energy 0 There are many different ideas on what pseudogenes actually do 5 Repeated Genes 0 Multiple copies of small genes that are clustered throughout the genome 0 Do not have to be tandemly connected to be transcribed 0 Not all these genes will go to make proteins but they help us to make proteins they are transcribed not translated o If they have a high copy number it means we need a lot of them Classical implies that it is protein coding those that actually make proteins Molecular modern definition transcribed read 0 there are a lot of genes that are never made into proteins they help make proteins and regulate Any gene has one requirement must be transcribed Exon coding phenotype part that makes you have black or blonde hair Introns quotintervening sequencesquot areas of genes that do no generally code for phenotype o The beginning and ending sequences of introns are highly conserved o Introns can become exons and exons can become introns so we can make multiple proteins off this transcriptional unit by playing around with the introns and extrons Structural View Flanking Region where transcription starts but is not the actual part that gets transcribed 539 Untranslated Region mRNA that is directly upstream from the initiation codon does not encode any any of the amino acids of a protein 339 Untranslated Region section of mRNA that immediately follows the translation termination codon affects stability of mRNA and translation of the mRNA proteincoding sequence 0 Promotor sequence indicates which of the two DNA strands is to be read as the template as well as the direction of transcription upstream TATA Box even simplest genes have some sort or tata box there has to be something to turn the gene on or off 0 CAAT Box sequence that is 60100 bases upstream from initial transcription site 0 Think about the in class car example TATA Box car key what starts the car CAAT Box gas pedal accelerates the car Enhancer region of DNA that activates transcription of a gene can be bound with proteins activators 0 can skip genes 0 Teminator marks the end of a gene after the terminator has been transcribed then transcription will stop PolyA Tail where many As are put at the 3 end of mRNA 0 Protects the end and is a signal to tell polymerase you are about to run out and need to look for the end of the gene 0 These nucleotides are not encoded in the DNA Humans have the same two genes but they overlap because the intron of one strand is the control for the exon on the other strand sometimes the genes do overlap We have double stranded DNA but we only use one side PostTranscriptional Regulation 0 Step one is the protect the message from the cell because the cell may mistake it for a virus 0 5 end comes off first so we can put a cap on it o the cap protects the end of the RNA from degradation and makes a hook which is important for translation 0 As soon as the message is available the cap is put on 3040 bases 0 Step two is to protect the other end this is done by adding a PolyA tail 0 The longer the tail is the longer it will stay in the cytoplasm 0 So if you want to use something multiple times you need a longer tail because every time you go through translation the tail gets smaller 0 Ex eggs in women 0 Step three we remove introns by splicing o Intron and exon picture in power point shows that RNA is a straight line and DNA is bowed out in singlestranded loop This is important because it tells us there are things in DNA that did NOT end up in message About Introns We don t find introns until we get to higher level systems 0 People began to question why we have introns are they splice joints that allow us to use the same scene over and over again exon shuffling theory o How do we get this pattern 0 Endosymbiotic theory some cells were 39invaded by bacteria39 and cell has evolved from this invasion shared genes between cytoplasm and mitochondria Splicesome large structure where splicing takes place 0 Splicing takes place in the nucleus before RNA moves to the cytoplasm hnRNA heterogeneous RNA 0 snRNP aka snurp remain in nucleus and helps with splicing o the splicesome is composed of five snRNPs Ribozyme concept of chicken or egg what came first amino acids and proteins or DNA 0 proteins don t store info so maybe DNA came first but DNA isn t catalytic However RNA is can act as an enzyme during splicing Spliceosome Assembly 0 httpswwwyoutubecomwatchv3rlziMRQZoU Lariat where we have taken a single piece of DNA and have curled it back on itself Alternative Splicing same process but the premRNA is spliced in more than one way making multiple mRNAs that can go on to be translated into different amino acid sequences 0 These amino acids then become different proteins 0 This process is important for protein diversity Central Dogma of Molecular Biology 0 Not really a dogma because it is not all correct 92015 1020 PM 92015 1020 PM
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'