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Biochem Block 2 Quiz
KYCOM Block 2
339
Biochemistry
Graduate
09/27/2012

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Term
describe the numbers of the human genome sequence
Definition
3 billion base pairs, 20000-25000 genes due to alternative splicing
Term
currently, what is the human genome sequence used for
Definition
genetic diagnosis
Term
what are the main achievements currently in bio technology
Definition
restriction endonucleases, DNA sequence, cloning DNA, creation of synthetic probes, PCR
Term
what is another name for a restriction enzyme
Definition
restriction endonuclease
Term
what does a restriction enzyme do
Definition
cleave specific DNA sequences
Term
what is a palindrome
Definition
a 4-8 base pair sequence that reads the same 5'-3' on both strands and is cleaved by an endonuclease
Term
what is the result after a restriction enzyme does his job
Definition
sticky and blunt ends
Term
describe a sticky end
Definition
overlaping sequence made by a restriction enzyme (zipper like)
Term
describe a blunt end
Definition
direct cut of a DNA sequence by a restriction enzyme (not zipper like)
Term
after a restriction enzyme cleaves, how is it possible that the area can be ligased if it was ruiened
Definition
3' OH and 5' phosphate are attached after clevage
Term
what is a restriction site
Definition
the sequence a restriction enzyme is cleaved, the palendrome
Term
describe the relationship between the recognition sequence length and the frequency of DNA cuts
Definition
the shorted the restriction site the more frequent it will be
Term
what is recombinent DNA
Definition
a compliation of cleaved restriction sites that have been ligated
Term
what type of restriction site cleavage is easier to work with
Definition
sticky ends
Term
describe the basic concept of DNA cloning
Definition
a restriction sequence is inserted into a cloning vector in host cells, DNA is cloned by the cell and amplified making recombinent DNA
Term
what is a vector
Definition
a DNA molecile that accepts foriegn DNA fragments
Term
what is a plasmid
Definition
simple bacterial vector
Term
what are the requirements of a vector for it to work with DNA cloning
Definition
autonomous replicationin the cell (so it needs an replication origin sequence), at least one restriction site, at least 1 gene for selection
Term
describe what a selection gene is and why it is needed
Definition
it ia gene within a vector that codes for some sort of selection, like an antibiotic resistance, because not all cells will have a vector with the restriction sequence in it and you need to weed out the ones that dont
Term
what are the common host cells for vectors
Definition
bacteria, yeast artificial chromosomes, retroviruses, yeast, phages
Term
what is a phage
Definition
a virus that infects bacteria
Term
what is a mammalian virus
Definition
a retrovirus
Term
what are the types of DNA libraries
Definition
genomic and cDNA
Term
what is the process of creating a genomic DNA library
Definition
take DNA from an organism, chop it up with restriction enzymes, ligate to a vector, let the host make many copies of each gene piece
Term
what does a genomic DNA library contain in the end
Definition
all sequences in the genome: introns, exons, promoters, etc
Term
what is the basic definition of a cDNA library
Definition
DNA compliment of mRNA that gives a snap shot of what was going on in that cell at that time
Term
describe the process of making a cDNA library
Definition
get a particular mRNA sequence from a cell, use reverse transcriptase to get a single DNA strand, use DNA polymerase to make it a double strand, put DNA into a vector and allow it to replicate
Term
in the end what does a cDNA library contain
Definition
no promoters, no introns, only mRNA
Term
how can a cDNA library be used after it has been made
Definition
put DNA clones into an expression vector to make mRNA then make protein
Term
describe the process of DNA sequencing
Definition
divide ssDNA, dNTPs, primers, and polymerases into 4 tubes into 4 tubes, add a specific dideoxyribonucleotide to each tube, synthesis proceedes until a dNTP is added in each strand, gel elecrtophoresis divides by length of products
Term
what do you need to do DNA sequencing
Definition
ssDNA, dNTPs, primer, polymerase
Term
what does DNA sequencing accomplish
Definition
determines the exact sequence of cloned DNA
Term
what is a probe used for
Definition
to identify DNA fragments
Term
what is a probe made of
Definition
ssDNA labeled (radioactivly usually) that can be hybrixised to ssDNA that is complimentary
Term
what is hybridization
Definition
when target DNA is made single stranded by a method like heat or chemicals
Term
if probes use ssDNA how do they not reanneal
Definition
nitrocellulose membrane solid supports
Term
what happens when a nitrocellulose membrane is exposed to a probe
Definition
if complimentary, probe will bind and can be identified by autotraiography
Term
how long is a small probes
Definition
2-30 base pairs
Term
how are small probes made
Definition
chemically synthesized oligonucleotides the same way synthetic primers are made
Term
what is the purpose of small probes
Definition
very specific, can identify a single base pair mutation
Term
how are large probes made
Definition
reverse transcription, PCR, etc.
Term
what is the function of large probes
Definition
can identify similar genes in different organisms or the same gene in different indiviguals that may not be exactly the same sequence
Term
what does southern blotting analize
Definition
DNA
Term
describe the process of southern blotting
Definition
isolate DNA, chop it with restriction enzymes, gel electrophotesis, denature DNA, blott it to immobilize it on the membrane, probe the blot
Term
what does southern blotting focus on
Definition
DNA
Term
what does northern blotting target
Definition
mRNA
Term
describe the requirements for northern blotting
Definition
do not need to make a single stranded, probe must be complimentary to the mRNA
Term
what does northern blotting specifically detect
Definition
expressed sequences
Term
why use nothern blotting
Definition
tissue or cell specific studies, measure gene expression
Term
what does a western blot target
Definition
proteins
Term
what is the probe in a western blot
Definition
antibody specific to the protein of interest attached to an enzyme
Term
what is the function of a western blot
Definition
quantative, tells how much protein you have
Term
what is a restriction fragment length polymorphism (RFLP)
Definition
genetic differences due to polymorphisms in one of the 99.9% noncding regions that are inheriently not harmful or do not containa phenotype
Term
what are the requirements to be considered a RFLP
Definition
create or deletes a restriction site, has more or less of a type of repeated sequence
Term
what are the causes of RFLP
Definition
single nucleotide polymorphisms, disease causing mutation, harmless changes, tandem repeats
Term
what can single nucleotide polymorphisms (SNPs) cause
Definition
create of abolish a restriction site, 90% of the genetic variation in humans
Term
what does a variable number of tandem repeats (VNTR) refer to?
Definition
human genome contains many regions where a sequence is repeated intandem many times that varies greatly from person to person that are not related and some between people related
Term
physycally, how is a RFLP produced
Definition
DNA is cleaved on either side of a VNTR
Term
what is a SNP
Definition
single nucleotide change that makes or abolishes a restriction site messing p the action of the restriction enzyme giving different sized fragments when run on a gel
Term
compared to VNTR describe the prevlience of SNP in the genome
Definition
SNPs are distributed through out
Term
what would we use SNPs
Definition
to locate a diseased gene (not that it is the disease causing mutation but they tend to be near them), to mark allales (disease markers)
Term
what does it mean that a tandem repeat is hypervariable
Definition
different in all people especially in those not related
Term
why use tandem repeats
Definition
not associated with disease, for paternity testing, forensics, molecular finger print
Term
what do you need to know to do a PCR
Definition
the flanking sequence around the sequence you want to amplify
Term
what are the advantages of PCR
Definition
amplify small amounts of DNA many times in a few hours, all in one test tube, DNA can be used for many reasons, amplify mutations to learn sequence, detect latent viruses, forensics, safer amniocentesis
Term
describe the process of PCR
Definition
1. design primer to find flanking sequences,
2. denature DNA to make ssDNA using heat close to water boiling point
3. add primer to get DNA polymerase started, cool a bit so primer can anneal
4. chain extension using dNTPs and DNA polymerase
5. repeat steps 2-4 20-30 times
Term
what is a flanking sequence
Definition
approx 20 base pairs on each DNA strand before the DNA sequence you want to do PCR on so a primer can identify it
Term
in PCR, when you cool after denaturing so the primer can bind, does the DNA strand not just re-anneal
Definition
because we add lots of primer to make that unlikley and the cooling is very fast
Term
what happens if in PCR the middle part of the DNA strand (between the primers) reanneals during cooling
Definition
DNA polymerase will push it back open when it comes by
Term
what is a latent virus
Definition
part of its life it is hidden in the genome at low levels, can be found with PCR
Term
how does PCR help forensics
Definition
small sample size is ok now, just amplify
Term
how did PCR make prenatal genetic testing safer
Definition
during amniocentesis, smaller sample size is used because we can just amplify, less invasive
Term
how can we assess mRNA levels
Definition
northern blot, microarray
Term
how are the results of a northern blot interperted
Definition
band = yes the mRNA was expressed, band width tells quantity
Term
what does a microarray show
Definition
mRNA expression for 1000s of genes at a time
Term
how does a microarray work
Definition
glass slide with 1000s of divits, each divit has ssDNA with a compliment to gene with bases pointed outwards, isolate the mRNA sample and make cDNA copy, if compliment is on slide it will bind to it. always comparing 2 samples
Term
how do you read microarray results
Definition
yellow: samples are equal in expression
black: only one sample had expression
red: one sample expressed more
green: the other sample expressed more
Term
what reads the results of a microarray
Definition
a machine that can analize the exact shades and determine conecntrations
Term
what does proteomics evaluate
Definition
proteins made in a cell, post translational modifications, turn over of proteins, tissue comparison, enzyeme modulations
Term
what does ELIZA stand for
Definition
enzyme linked ammunosorbent assay
Term
how does ELIZA work
Definition
protein is linked to an enzume and put in a 96 microwell plate, antigen is bound to plate well, probe with antibody is linked to the enzyme, add colored substrate to see how much protein bound, bound protein = protein made in cell
Term
how do you read the results of a western blot
Definition
gives color reaction and exact band size
Term
what protein / DNA expression techniques use a gel
Definition
southern, northern, and western blot, proteomics, PCR (maybe)
Term
what protein / DNA expression techniques are quantative
Definition
norther and western blots, microarray, elisa, proteomics, PCR sometimes
Term
what protein is affected by a sickle cell anemia mutation and how
Definition
b-globin by eliminating a restriction site
Term
what type of mutation is involved in sickle cell anemia
Definition
a point mutation creating a RFLP
Term
why is sickle cell anemia a special type of RFLP
Definition
because it is one of the few times where the RFLP mutation is disease causing
Term
what are the ways you can test for sickle cell anemia
Definition
PCR, southern blot, allele specific olegonucleotide probes
Term
explain how to interpert the results of a southern blot for sickle cell anemia
Definition
sickle cell has one larger (higher on gel) band, a carrier has two bands, a normal allele will have one smaller band
Term
what type of inheritence does sickle cell have
Definition
recessive, a heretozygote will have no symptoms
Term
explain the process of doing a PCR to detect sickle cell anemia
Definition
design a primer to flank the B-globin gene, amplify the mutation region, digest the fragment with a restriction enzyme and run a gel
Term
where does the specificity come from when running a PCR to determine sickle cell anemia
Definition
designing a primer for the mutation region
Term
describe how to read the results for a PCR on sicle cell anemia
Definition
there will be one larger (higher on gel) band for sickle cell and two smaller bands for a normal patient
Term
describe the process of allele specific olegonucleotide probing
Definition
get samples from people, make two wells per person, probe one well with the normal gene and one with the mutated gene, add in the samples, see which well has the reaction
Term
what types of mutations can allele specific olegonucleotide probing find
Definition
point mutations
Term
what gene is mutated in cystic fibrosis, what does this gene have a role in
Definition
CFTR, chloride transport
Term
what is the most common lethal genetic mutation in caucasions
Definition
cystic fibrosis
Term
what are some of the symptoms of cystic fibrosis
Definition
chloride in sweat, lack of chloride secretion in the lungs leading to infection and mucus build up, build up of mucus in the pancreas, death around age 30
Term
what type of mutation affects most people with cystic fibrosis, what amino acid is missing due to it
Definition
deletion, phenylalaline
Term
what test do we use to determine cystic fibrosis
Definition
ASO probing, PCR
Term
what type of inheritence is cystic fibrosis
Definition
recessive, need two mutant genes to get the symptoms
Term
describe how to do a PCR to test for cystic fibrosis
Definition
possible deletion area is flanked making different size products depending on if the deletion area is there or not
Term
describe how to interpert the results of a PCR for cystic fibrosis
Definition
the mutant will have one smaller band (it weights less because of the cut due to the mutation), the normal will have one larger band, a carrier will have both bands
Term
describe the process of allele specific olegonucleotide probing
Definition
get samples from people, make two wells per person, probe one well with the normal gene and one with the mutated gene, add in the samples, see which well has the reaction
Term
what types of mutations can allele specific olegonucleotide probing find
Definition
point mutations
Term
what gene is mutated in cystic fibrosis, what does this gene have a role in
Definition
CFTR, chloride transport
Term
what is the most common lethal genetic mutation in caucasions
Definition
cystic fibrosis
Term
what are some of the symptoms of cystic fibrosis
Definition
chloride in sweat, lack of chloride secretion in the lungs leading to infection and mucus build up, build up of mucus in the pancreas, death around age 30
Term
what type of mutation affects most people with cystic fibrosis, what amino acid is missing due to it
Definition
deletion, phenylalaline
Term
what test do we use to determine cystic fibrosis
Definition
ASO probing, PCR
Term
what type of inheritence is cystic fibrosis
Definition
recessive, need two mutant genes to get the symptoms
Term
describe how to do a PCR to test for cystic fibrosis
Definition
possible deletion area is flanked making different size products depending on if the deletion area is there or not
Term
describe how to interpert the results of a PCR for cystic fibrosis
Definition
the mutant will have one smaller band (it weights less because of the cut due to the mutation), the normal will have one larger band, a carrier will have both bands
Term
what type of inheritence is PKU
Definition
autosomal recessive
Term
why are all newborns screened for PKU
Definition
because the symptoms can be avoided with a special diet
Term
what process is inhibited during PKU
Definition
phenylalanine turning into tyrosine
Term
why can we use ASO probing or PCR to find PKU
Definition
because there are over 400 mutation site possibilities and you would have to make over 400 primers with special flanking regions or have over 400 wells for ASO
Term
what are the symptoms of PKU
Definition
mental retardation
Term
how many exons could have a PKU causing mutation
Definition
13
Term
what types of mutations could cause PKU
Definition
mostly missense and some splice, nonsense, insertions, deletions
Term
describe how to do RFLP analysis to determine PKU
Definition
collect DNA from many family members including 1 person with the disease and the patient, find a RFLP marker that is near the disease site, do a southern blot on the RFLP marker and compare the patient with the normal, carriers, and affected family members to find the patient's result
Term
what kind of mutation cause myotonic dystrophy and of what gene
Definition
3' non-coding trinucleotide repeat of a protein kinase gene
Term
what is the most common adult muscular dystrophy
Definition
myotonic dystrophy
Term
describe how to do RFLP comparison to determine muscular dystrophy
Definition
digest part of the RFLP and get an identifiable sequence, compare to family members who are affected or not, the mutant allele may be different in each person but you compare to the family members so you can see what normal looks like in that family
Term
what happens to trinucleotide repeats over time
Definition
they get bigger with each generation
Term
why can we do PCR on a trinucleotide repeat
Definition
PCR can flank the expansion region but when it gets too big it becomes difficult for PCR to amplify the region
Term
what techniques do you use to detect HIV
Definition
immunoassays: ELIZA and western blot
Term
why is it difficult to detect HIV early
Definition
because it takes years for the symptoms to develop because it takes a long time for antibodies to form
Term
at what point can you test for HIV
Definition
around 6 months after infection there should be enough antibodies, but you can do it earlier but retest after 6 months
Term
how to use ELIZA to test HIV
Definition
bind proteins to the wells and add the HIV antibody, add the sample to the wells, if there is an HIV antibody there will be a reaction causing color change
Term
why do we also do a western blot to test for HIV
Definition
ELIZA is super sensitive and could give a flase positive so you want to test the protein to make sure it is the right size and is HIV
Term
how do you do a western blot to test for HIV
Definition
do electrophorsis to seperate sample, probe for a protein reaction and verify the protein by size
Term
how has PCR revolutionized HIV testing
Definition
test can be done immediatly because you need less sample, you can PCR for the provisus to test time now, you can do reverse transcription PCR for HIV itself, you can monitor HIV over time (quantative)
Term
how is paternity testing done
Definition
design a primer to flank VnTR molecular fingerprint and amplify, stain for any DNA present (no probe) and compare to family
Term
what is the paternity index
Definition
because VNTRs are not perfect between family members different states require you to test a different amount of VNTRs before making a decision on paternity
Term
gene
Definition
basic unit of inheritence
Term
locus
Definition
location of a gene on a chromosome
Term
allele
Definition
alternative form of a gene at a locus
Term
genotype
Definition
genetic constitution of a person
Term
phenotype
Definition
observed expression of a genotype
Term
homozygous
Definition
identical allels on each locus of a chromosome pair
Term
heterozygos
Definition
different allels on each locus of a chromosome pair
Term
dominent
Definition
condition in homozygotes and heteroxygotes where only one copy of the gene is needed for the phenotype
Term
recessive
Definition
condition in homozygotes and heteroxygotes where two copies of the gene are needed for the phenotype
Term
autosome
Definition
non sex chromosome
Term
how many autosomes do we have
Definition
22
Term
sex chrommosome
Definition
X or Y chromosome
Term
diploid
Definition
2 copies of each chromosome
Term
haploid
Definition
1 copy of each chromosome
Term
somatic cell
Definition
body cell
Term
gamate
Definition
sex cell, haploid egg or sperm
Term
single gene disorder
Definition
single gene mutated, transmitted in simple patterns
Term
what are the types of single gene disorders
Definition
autosomal, recessive, X linked
Term
chromosome abnormality
Definition
deviation in number of chromosomes
Term
structural chromosome abnormality
Definition
more, less, or wrong chromosome info
Term
multifactoral traits
Definition
multiple genes and non-genetic (enivormental) influences
Term
what shape and color is an asympatmatic male
Definition
white square
Term
what shape and color is an asymptamatic female
Definition
white circle
Term
what shape and color is an symptamatic male
Definition
black square
Term
what shape and color is an symptamatic female
Definition
black circle
Term
what shape and color is an dead male
Definition
square with line through it
Term
what shape and color is an dead female
Definition
circle with line through it
Term
what shape shows two are mating
Definition
line between circle and square
Term
what shape shows two related people are mating
Definition
2 lines between circle and square
Term
what shape shoes dizygotic twins
Definition
single line that branches from parents that splits to the two twins
Term
what shape shows monozygotic twins
Definition
triangle with points being parents and two kids
Term
how can you tell by a pedigree that a disease is autosomal dominent
Definition
affected person in every generation, always one affected parent, affects either sex, has male to male transmission
Term
what proteins are associated with autosomal dominate disorders
Definition
non-catalytic
Term
what diseases are autosomal dominate
Definition
familial hypercholsterlemia, huntingtons, myotonic dystrophy, neurofibromastosis type 1, osteogenesis imperfecta, marfans syndrome
Term
what is the recurrance risk
Definition
probability of disease being passed to offspring with each reproductive event not affecting the occurance of another in the data
Term
when determining recurrance risk in autosomal dominent disorders what does an upper case letter mean
Definition
dominent allele (nothing to do with mutant or not)
Term
when determining recurrance risk in autosomal dominent disorders what does an lower case letter mean
Definition
recessive allele (nothing to do with mutant or not)
Term
what is the most common autosomal dominant cross, what is the percentage of having affected children
Definition
aa x Aa, 50% affected
Term
in a pedigree, what trends show it is an autosomal recessive disorder
Definition
affected person normally has unaffected parents, either sex affected, both parents are at least carriers, male to male transmission, skipping of generations
Term
what proteins are involved in autosomal recessive disorders
Definition
catalytic
Term
what are some autosomal recessive disorders
Definition
sickle cell anemia, cystic fibrosis, pku, tay-sacs
Term
what familial situation usually causes autosomal recessive disorders
Definition
incestous
Term
what type of genetic cross is commonly involved in autosomal recessive diseaes, what percent of the children are affected
Definition
Aa x Aa giving a 25% chance of disease
Term
when doing a cross for chance of inheritence with an autosomal recessive disorder, what does a lower case letter signify
Definition
mutant allele
Term
what are the two categories of diseases associated with the X gene
Definition
x-linked dominent and x-linked (recessive)
Term
what type of genetic disease is fragile x
Definition
it is considered to be x-dominent sometimes and x-linked others
Term
who is affected by x linked disorders
Definition
only or mostly males
Term
in a pedigree, how can you tell a disorder is x linked
Definition
usually unaffected parents, male inherits diseased allele from mom, no male to male transmission
Term
what are some x-linked diseases
Definition
duchene and becker muscular dystrophy, lesh-nyhan syndrome, glucose-6-phosphate dehydrogenase deficiency, hemophilia A and B, menches
Term
what is the most common genetic cross involved in x-linked diseases, what percent of children will be affected
Definition
XY x Xx, 25%
Term
what does mitochondrial DNA encode for
Definition
13 proteins, 2 rRNA, 22 tRNA
Term
on a pedigree, how can you tell if a disorder is mitochondrial
Definition
affected female affects all children, affected male affects none of the children, males and females affected,
Term
what diseases are due to mitochondrial inheritance
Definition
leber's hereditary optic neuropathy, neuropathys, myopaths, cardiomyopaths
Term
how do you calculate the risk of recurrance in mitochondrial diseases
Definition
you don't it does not follow mendilian genetics
Term
what are the symptoms of leber's hereditary optic neuropathy
Definition
blindness, rapid, irreversable, begins in central field, around age 30, optic atrophy
Term
what is wrong with the proteins in osteogenesis imperfecta
Definition
defect in structural proteins
Term
what diseases have a defecit in regulatory proteins
Definition
familial hypercholsterloemia, myotonic dystrophy
Term
what is a gain of function disorder
Definition
normal protein becomes too toxic
Term
what disease causes a gain in protein function, what does it affect
Definition
huntington disease causes toxic effects to neurons
Term
why type of inheritence is neurofibromatosis type 1
Definition
autosomal dominent
Term
what is mutated in neurofibromatosis type 1
Definition
regulatory protein involved in controlling the cell cycle
Term
what are the symptoms of neurofibromatosis type 1
Definition
cafe-au-lair spots, multiple neurofibromas, axillary freckling, lisch nodules in eye, variable expression
Term
what type of inheritance is marfans syndrome
Definition
autosomal dominent
Term
in marfan syndrome what is mutated, in what major areas is it located
Definition
fibrillin mutation, ECM and connective tissue
Term
what are the symptoms of marfan syndrome
Definition
thin long limbs, long fingers, hypermobile joints, myopia, detached lens, aortic aneurysm
Term
what is pleiotropy
Definition
1 mutation affects multiple organ systems, common
Term
what disease is an example of pleiotropy
Definition
marfan syndrome
Term
what type of inheritance is thalassemia
Definition
autosomal recessive
Term
what gene is affected in alpha-thalessemia, what is the result
Definition
insufficient synthesis of alpha chain of hemaglobin, beta globin acclumulates
Term
what gene is affected in beta-thalessemia
Definition
insufficient synthesis of beta chain of hemaglobin, alpha chain accumulates
Term
where in the world are thalassemia diseases common
Definition
mediterian sea, africa, southeast asia
Term
describe the globin content in a normal hemaglobin
Definition
2 beta globin from 2 normal genes make 2 beta chains, 4 alpha globin from 2 copies of 2 adjacent genes make 2 alpha chains
Term
what chromosome is alpha globin on
Definition
16
Term
what chromosome is beta globin on
Definition
11
Term
so if there are more alpha globin genes and less beta globin why isnt there always more alpha globin
Definition
the body accounts for this and we still get equal production
Term
describe the globin content of a fetal hemaglobin
Definition
2 gamma chains and 2 alpha chains
Term
what makes fetal hemaglobin functionally different from adult
Definition
it has a higher affinity for oxygen so it can pull oxygen from the mother;s hemaglobin
Term
when does fetal hemaglobin go away, what replaces it
Definition
from 6 mo - 2 yrs old it decreases and is replaced by beta globin
Term
when someone has beta thalasemia, they have a decrease in beta Hb and increase in alpha Hb, why can't they use use 4 alpha Hb and be fine
Definition
a Hb with 4 alpha Hb chains is insoluble and percipitates and is removed by the spleen and other blood cleaning organs due to 'damage'
Term
what is hemolytic anemia
Definition
anemia due to thalasemia
Term
what does it mean when said that beta-thalasemia has compounded anemia
Definition
beta globin is decreased giving anemia, and the 4 alpha globin Hb that took its place are removed giving further anermia
Term
describe the genes of a beta thalasemia carrier
Definition
1 normal copy and 1 mutated
Term
describe the genes of a person affected with beta thalassemia
Definition
2 mutated copies of the gene with various intensities B0 or B+ and combinations of these intensities
Term
what is a B0 (beta o) mutation
Definition
total absence of the functional B globin in that copy of the gene
Term
what is a B+ (beta +) mutation
Definition
leads to reduct beta globin but it is still normal
Term
what may be some of the reasons for a beta + mutation
Definition
may be a problem with the promoter, not getting sufficient promotion of transcriptioon but do get some
Term
what are the symptoms of thalassemia minor
Definition
usually asymptamatic of have mild anemia which may be mistaken for Fe deficiency anemia.
Term
how do you diagnose thalassemia minor
Definition
hemaglobin electrophoresis or blood work
Term
describe the genes of someone with beta thalassemia minor
Definition
carrier, one affected gene
Term
what are the symptoms of beta thalassemia major
Definition
severly reduced or no Hb production, severe anemia, hepatosplenomegaly, skeletal deformities especially in face and scull, bone marrow expansion, increased systemic Fe accumulates in liver and heart
Term
why is beta thalassemia not seen in babies
Definition
because they dont use beta globin until 6 mo old, they use gamma
Term
why is there hepatosplenomegaly in b-thalassemia
Definition
because the liver and spleen are trying to make new RBC and are getting rid of so many that they swell
Term
what does someone with b-thalassemia get skeletal and face deformities
Definition
because the bone marrow swells due to trying to make so many RBC
Term
how do you treat thalassemia major
Definition
regulat blood transfusions (every 2-4 weeks) combined with Fe chelation therapy, bone marrow transplants, potential gene therapy
Term
what are the symptoms and treatment of thalassemia intermedia
Definition
vary a lot, defined on clinical symptoms, treat with occasional blood transfusions
Term
what is gamma-globin synthesis continued into adulthood
Definition
turning the gene on could kill of b-thalasemia but people could have a hard time releasing O2, so less athletics, or could kill baby if pregant becase mom is stealing all the o2
Term
in regard to genes, what usually causes alpha-thalassemia
Definition
usually due to missing genes, classified by how many are missing
Term
in alpha-thalassemia, what is the phenotye of aa/aa, what are the symptoms
Definition
normal, none
Term
in alpha-thalassemia, what is the phenotye of -a/aa, what are the symptoms
Definition
silent carrier, none
Term
in alpha-thalassemia, what is the phenotye of --/aa, what are the symptoms
Definition
alpha-thalassemia trait, symptoms like thalassemia minor or are asymptmatic
Term
in alpha-thalassemia, what is the phenotye of -a/-a, what are the symptoms
Definition
alpha-thalassemia trait, symptoms like thalassemia minor or are asymptmatic
Term
in alpha-thalassemia, what is the phenotye of --/-a, what are the symptoms
Definition
hemaglobin H (HbH) disease, symptoms like thalassemia intermedia
Term
in alpha-thalassemia, what is the phenotye of --/--, what are the symptoms
Definition
hydrops fetalis, cannot support life because babies need alpha thalasemia unline beta
Term
what does hydrops fetalis mean
Definition
not specific to alpha-thalassemia, general term for death in utero with adema and swelling
Term
what happens in utero to the globin molecule when someone has alpha-thalassemia
Definition
gamma-globin forms tertameres (Hb Bart)
Term
what happens in utero when someone has alpha thalassemia with 1 copy of alpha globin
Definition
evuntally B-globin tetramere HbH forms
Term
what is the difference between HbH / HbBart and the beta-globin tetramere, what differences does this cause in the symptoms
Definition
they are less toxic which is why someone with any alpha globin at all has less severe symptoms that someone with b-thalassemia
Term
in regards to x-linked genes, what is the word that classifies males, what does this mean
Definition
hemizygos, they only need one copy of the gene to show symptoms wether it is dominent or recessive
Term
what gene is damaged in hemophellia a
Definition
blood clotting factor 8
Term
what gene is damaged in hemophelia b
Definition
blood clotting factor 9
Term
what type of mutations can cause hemophelia
Definition
deletions, nonsense, DNA inversions
Term
what cellular difference leads to difference severities in the symptoms of hemophelia
Definition
different mutations leading to different levels of the clotting factors in the body
Term
how can you tell the differences, in regard to symptoms, between hemophelia a and b
Definition
they have the same symptoms so you need to do a blood test or gene sequencing
Term
is hemophelia common or rare
Definition
common
Term
what type of hemophelia is more common
Definition
a
Term
what are the symptoms of hemophelia
Definition
prolonged bleeding, intercranial hemorraging, easy bruising, hemarthorsis
Term
what is hemophelia often mistaken for
Definition
a vitamin k deficiency
Term
what signs of hemophelia are often noticed at birth
Definition
too much bleeding during circmucision or cutting umbilical cord, intercranial hemmorage that can cause death
Term
what is hemarthorsis
Definition
bleeding into the joints
Term
what is the most frequent cause of death in people with hemophelia, why
Definition
AIDs, because treatment is factor replacement therapy and we used to use concentrated human plasma and during purification viruses are not eliminated
Term
why is AIDs less of a problem for hemophelia patients now
Definition
because we have better screening processes and are moving towards recombinent clotting factors and potential gene therapy
Term
what worries do people with hemophelia still have today when doing factor replacement therapy
Definition
some viruses not eliminated or tested for still, like hepititis
Term
in duchenne and becker muscular dystrophy what gene is affected
Definition
dystrophin gene in both diseases
Term
in duchenne and becker muscular dystrophy, they affected gene causes problems in cells of which areas
Definition
cytoplasm of muscle (all kinds) and some neuro tissue
Term
why does the gene for duchenne and becker muscular dystrophy have a higher mutation rate and get new mutations
Definition
because it is so large
Term
why type of mutation causes duchenne muscular dystrophy
Definition
frameshift insertion/deletion, also leads to a trunkated protein due to the potential of an early stop codon
Term
compare duchenne muscular dystrophy to myotonic muscular dystrophy in severity and frequency
Definition
duchenne muscular dystrophy is more common overall and more sever, myotonic is only the most common adult muscular dystrophy
Term
what are the symptoms of duchenne muscular dystrophy
Definition
apparent at 5 yrs, 10-12 years wheelchair, muscle atrophy, progressive, cognative impairment, death due to decreased respiratory function causing infections and decreased cardiac function around 20 yrs
Term
what type of deletion is becker muscular dystrophy
Definition
non-frameshift insertion/deletion
Term
what is the differences in the gene for becker muscular dystrophy vs duchenne
Definition
the gene makes a partially functional protein causing more mild symptoms
Term
what are the symptoms of becker muscular dystrophy
Definition
same general progression as duchenne but takes longer, onset is about 11 yrs and death 42
Term
what is the treatment for duchanne and becker muscular dystrophy
Definition
only therapy, gene therapy has show potential in animal models but the large gene makes things difficult
Term
what is another name of x-inactivation
Definition
lyonization
Term
why do we need x-inactivation
Definition
because gemales have 2 X and males only 1, so in theory, females would make double of all the proteins which they do not need
Term
what is x-inactivation
Definition
where one chromosome in females is shut off and not available for transcription
Term
what is the inactivated x chromosome called
Definition
barr body
Term
how are the genes of a barr body shut off
Definition
highly methlyated
Term
in what phase are the nuclei of a barr body when they are shut off
Definition
interphase
Term
at what stage does the cell shut off the barr body duriing the development
Definition
the 100 cell stage
Term
how does the cell decide which X chromosome to shut off during x-inactivation
Definition
it is random but after the 100 cells choose, all of their decendents will have the same one shut off
Term
what is ment when said that x-inactivation is incomplete
Definition
the entire barr body isn't shut off, about 10% is able to be transcribed
Term
what does incomplete x-inactivation explain
Definition
why some females show traits of mutant with only one copy mutated and one normal gene and why the symptoms are less severe (because they only have one X it makes it almost like they can get recessive x-linked diseases like males, but because they are females and do have normal genes it is less severe)
Term
why does it matter which x is shut off in each cell during x-inactivation
Definition
some come from mom and some come from dad and the one left on is randomly chosen, this gives potential for good genes to be deactivated and bad ones to stay active (or vice versa). unlucky choosing can produce more bad genes than good ones even though the female would normally be an asymptamatic carrier and they will then express the disease
Term
how can severe hemophelia occur in females
Definition
because unlucky shutting off of the barr body can make a carrier express more of the mutant genes, giving them the full symptoms anyways
Term
what type of mutation is fragile x
Definition
trinucletide repeat expansion in the 5' non coding region
Term
what are the symptoms of fragile x
Definition
long face, large mandible, large everted ears
Term
what is the most common know cause of autism
Definition
fragile x
Term
what is the most common inherited mental retardation
Definition
fragile x
Term
why can't fragile x be considered x-linked dominent
Definition
dominent should have 2x as many females as males affected and there are quite of bit of females affected but not more than males
Term
why can't fragile x be considered x-linked recessive
Definition
because recessive means that almost no females should be affected and quite a few are
Term
when a female gets fragile x, how do her symptoms differ
Definition
they are more variable and less severe
Term
how many fragile x mutations does a female with fragile x have, explain your answer
Definition
1 or 2. they can get symptoms with only one because of the barr body situation where it makes only one x chromosome anyways, or they can have two
Term
what type of x-linked disease is fragile x most likley to be in conclusion, why
Definition
x-linked recessive, because you can't say dominent/recesive when your only expressing one gene as it has seen to be the case in all males and most all females with fragile x
Term
What disorder type is delayed age of onset a symptom of
Definition
Single gene disorders
Term
What disorders have a delayed age of onset
Definition
Huntingtons, myotonic dystrophy
Term
What is locus heterogeneity
Definition
Same phenotype is caused by mutations at different loci
Term
What disease has locus heterogeneity, in regards to inheritance what does this cause
Definition
Elhers danlos syndrome, several inheritance patterns
Term
What types of instance can elhers danlos have
Definition
Autosomal dominant and recessive, x linked
Term
What is the mutation in elhers danlos autosomal dominant
Definition
Collagen gene
Term
What is the mutation in elhers danlos autosomal recessive, what process does this disrupt
Definition
Mutation in Lysol hydroxylase, processing collagen
Term
What is the mutation in elhers danlos x linked recessive, what does this cause
Definition
Mutation in copper binding protein gene on the x chromosome leading to reduced copper in serum (copper is involved in lysyloxidase which causes cross linking in collagen)
Term
how do all diseases start
Definition
with a new mutation
Term
what are the characteristics of a disease that in most cases comes from a new mutation
Definition
high mortality or decreased fertility
Term
what categories of disorders often come from a new mutation (dominent, recessive, autosomal, X)
Definition
autosomal dominent, x-linked recessive
Term
what disease did we talk about is an example of a new mutation, what inhertience model is it
Definition
duschenne muscular dystrophy, x-linked
Term
what is anticipation
Definition
most recent generations have earlier onset and more severity
Term
what mutation is associated with anticipation, how does the aspects of this mutation correlate with the definition of anticipation
Definition
trinucleotide repeats, more repeats means more severity, there are more repeats with each generation
Term
what diseases are and example of anticipation
Definition
myotonic dystrophy, huntington, fragile x
Term
what do we use to evaluate population genetics
Definition
hardy weinberg equlibrium
Term
what are the assuptions that make the hardy weinberg equlibrium possible
Definition
assume 2 alleles (p and q)
the frequency total is 100%: so p + q = 1
Term
how do you determine the frequency of the genotype qq
Definition
q squared
Term
how do you determine the frequency of the genotype pp
Definition
p squared
Term
how do you determine the frequency of the genotype pq
Definition
2pq
Term
what are the factors that affect genetic variation
Definition
mutations, natural selection, heterozygote advantage, genetic drift, gene flow
Term
how much do mutations affect the genetic variation
Definition
it is different in every population, in humans not that much
Term
what is natural selection
Definition
influce on gene frequency by selecting for survival or fertility making disease genes more rare
Term
what is fitness
Definition
natural selection for fertility
Term
which types of genes are exposed to selection more often
Definition
dominent
Term
why are recessive genes exposed to selection less often
Definition
because they are often hidden in the heterozygote
Term
what is the heterozygote advantage
Definition
when a heterozygote mutation is selected for because it prevents other, worse diseases
Term
what are examples of the heterozygote advantage
Definition
sickle cell helps milaria, thallesemia helps malaria, cystic fibrosis may help with typhoid fever, G6PD helps malaria
Term
why in sickle cell is the carrier not affected
Definition
because in the carrier the plasmodium survives poorly giving malaria resistance without too many side effects
Term
what is genetic drift
Definition
in populations with a finite small size rare genes are present because they founders had them and there wasn't much room for genetic variance
Term
what is another name fo genetic drift
Definition
founder effect
Term
what is a disease that is an example of the founder effect
Definition
ellis van cerveld
Term
what type of inheritence is ellis van cerveld
Definition
autosomal recessive
Term
what are the symptoms of ellis van cerveld
Definition
usually in old order amish communities, polydactyly (short limbed dwarfism)
Term
what gene is effected in ellis van cerveld
Definition
EVC gene
Term
what is gene flow
Definition
the exchange of genes amoug populations
Term
what is the cause of methemoglobinemia
Definition
elevated Met Hb in the blood which has oxidized Fe so it cannot pick up oxygen as well
Term
what are the symptoms of methemoglobinemia
Definition
blue skin, blood that upon introduction to air stays brown
Term
what happens to normal deoxygenated blood upon esposure to air
Definition
it immediatly reoxygenates and turns red
Term
what is another name for methemoglobinemia
Definition
chocolatecyanosis
Term
normal people do get met hb, why are they not blue
Definition
because normally the body makes enzymes to reduce it
Term
how can someone aquire methemoglobinemia
Definition
oxidative stress: drugs, antibiotics, thromethoprimcane, anaesthetics, compounds with nitrates
Term
why are infants under 6 mo more prone to methemoglobinemia, what should they stay away from because of this risk
Definition
they do not have adult levels of the enzymes that combat met hb yet, nitrates ingested in food / water can cause it
Term
what is defective in congenital methemoglobinemia
Definition
decreased NADH met hb reductace which normally reduces Fe so it can pick up oxygen, increased HbM and HbH. thee enzyme is active just not efficient
Term
what is another name for NADH met hb reductase
Definition
diaphorase I
Term
what are diseases with congenita methemoglobinemia
Definition
pyrivate kinase deficiency, G6PDH deficiency
Term
how is methemoglobinemia treated
Definition
methlyine blue, electron donor reduces Fe back to normal so it can pick up oxygen. gives blue pee
Term
what is the mutation in hippel lindau syndrome
Definition
nutation in tumor supressor,
Term
many times hippel lundeau is cause by what type of tumor
Definition
pheochromocytomas: tumors in the adrenal gland
Term
what symptoms does a pheochromocytomas cause, why
Definition
explosive temper, due to excessive production of adreniline
Term
what genetic trend is lynch syndrome and example of
Definition
the founder effect
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