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256 Cards in this Set
- Front
- Back
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clastogen
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material that causes breaks in chromosomes via deletion, addition or rearrangement.
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caspases
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intracellular proteases that fuction as initiators and effectors of apoptosis. They cleave the aspartate-cysteine bonds in proteins.
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oncosis
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cell death characterised by mitochondrial swelling in ischemic cell death.
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MMP
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matrix metallo-proteinase (endopeptidase which is a prodeath protein released when TNF / FAS factors bind.
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mitotic catastrophe
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A type of cell death- abnormal activation of CYCLIN B/CDK1-
Occurs in meta/anaphase - cellular checkpoints ignored / damage = caspases activated. signs are multi and micro nucleation leading to aneuploidy and apoptosis. |
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TNF
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tumour necrosis factor - Induces inflammation, cell death and is activated by macrophages.
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Death receptors are..?
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FAS / TNF
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DIABLO
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direct IAP binding protein with low pl
Binds to and inhibits IAP (inhibitor apoptosis protein) |
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IAP
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inhibitor apoptosis protein -> inhibits caspase 3 = no apoptosis
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pyknosis
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chromatin condenses next to the nuclear membrane in apoptosis
(irreversible) |
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karyorrhexis
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destructive fragmentation of the nucleus, the nuclear membrane becomes permeable.
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PARP
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"poly - ADP - ribose polymerase" A nuclear protein involved in DNA repair, it can induce AIF (apoptosis inducing factor) to mitochondria to START APOPTOSIS
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AIF
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apoptosis inducing factor (stimulates mitochondria)
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P53
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A tumour suppressor protein
conserves the genome & prevents mutations. Activates DNA repair, induces growth arrest and starts apoptosis |
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CAD
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"caspase activated deoxyribonuclease"
hydrolyses dna to 180-200 bp fragments |
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APO-1
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apoptosis antigen 1 = FAS receptor = TNF receptor
synonyms of each other |
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Specimen used in apoptosis?
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"Caenorhabditis Elegans" a nemutoda, it has 1030 cells and 131 die during development via apoptosis
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Specimen used in cytoplasmic streaming?
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Elodea.
cyclosis due to actin microfilaments. |
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Specimen to see flagella?
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Euglena.
movement of microtubules |
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Specimen to see cillary beating?
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Paramecium
movment of microtubules |
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cytochrome c
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normal= part of the ETC inner membrane of M
apop= released from M, binds to APAF-1 and ATP to form the apoptosome |
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APAF-1
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"apoptotic protease activating factor" binds to ATP and cytochrome c to form the apoptosome
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Apoptosome
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cleaves procaspase 9 = caspase cascade! Initiates apoptosis
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Annexin V
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Is a PHOSPHOLIPID, used to stain phosphatidyl serine with FITC to see protein makers on the cell surface.
FITC = "fluorescein isothiocyanate" |
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FITC
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"flourescein isothiocyanate" flourochrome LABEL used to bind to annexin v
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microflourimetry
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Quantitative test to tag cell components with flourescent molecules.
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microscopy
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qualitative test of a specimen under magnification
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flourescence
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absorption of light by flourochrome, electrons promoted, return to ground state and longer wavelengths of light are emmited with heat.
The emmision energy is flourescence |
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epi-illumination
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light goes through the objective and illuminates the specimen
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fluorescein
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Direct fluorochrome with unchanged quantum yeild
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Acridine orange
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A METACHROMATIC direct flurochrome probe with unchanged quantum yield.
DNA = yellow RNA = orange |
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Autoflourescence
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natural emission of light-
chlorophyll, lipofuscin, Hb, myoglobin, phytochromes, flavins, tryptophan |
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direct flourescence
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flourochromes change QY after binding to cellular structures.
DAPI - DNA BLUE Hoechst stain |
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DAPI
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4'6'- diamidino-2-phenylindole
A direct flourescent stain. DNA = BLUE |
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Flourescent label
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covalently binds to specimen
Phalloidin, DAPI |
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Flourescent probe
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non-covalent binding to specimen
acridine orange |
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Unchanged quantum yield direct flourescent stains
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Acridine orange
Flourescein |
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Changed quantum yield direct flourescent stains.
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DAPI
HOECHST DiOC6 |
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Phalloidin
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labels F actin microfilaments, when conjugated with a flurophore
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Flourescence advantages
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High sensitivity, speed, safety,
good contrast, fixed specimen |
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Indirect flourescence
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Antibody sandwich, FISH labeled oligonucleotides
another molecule between cellular target and flourescent molecule |
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FISH
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flourescence insitu hybridization
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Flourescence disadvantages
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Photobleaching, expensive, resolution limit, toxic to cells
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BRET
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bioluminescence resonance energy transfer
LUCIFERASE railroad worm, squid, bacteria, fireflies (LUCIFERIN) |
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GFP
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Green flourescent protein
Aequorea victoria jelly fish. Transduces blue chemiluminescence to green flourescent light. |
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cyropreservation compounds
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polyethyleneglycol
glycerol dimethyl sulfoxide |
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native stains
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DO NOT KILL CELLS
acridine orange, neutral red, janus green |
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Anti-apoptotic proteins
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Bcl-2 (B-cell lymphoma 2)
activates or suppresses based on conc. on the mitochondrion membrane, regulates the release of cytochrome c. IAP / XIAP (x-linked) survivin (BIRC5 gene) |
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Activation genes of A
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BAX family
(Bcl-2 associated X protein) promotes apoptosis |
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Intrinsic A pathway
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Injury to the cell
1. Mitochondria -> cyto C -> APAF-1 activates caspase 3 2. Diablo/smac -> counteract IAP = +caspase 3 & cleavage of PARP 3. ER stress -> mitochondria stress etc... |
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Extrinsic A pathway
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FAS ligand binds to FASr
Fas associated death domain (or TNF) Procaspase 8 cleavage process ends with CASPASE 3 cleavage of PARP and A |
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Effects of A on mitochondria
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Cyto C released + AIF, -ATP, Ca2+ released,
Activation of endonucleases (caspases) production of O2 radicals, + permeability. |
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Effects of A on plasma membrane
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Externalisation of phosphatidylserine
stain with Annexin v + FITC |
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Effects of A on cytoskeleton
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microfilaments = actin forms blebs
intermediate filaments = cytokeratin fragmentation microtubules not affected |
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Regulation of apoptosis?
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cytokines - TNF, FAS, GF
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necrosis characteristics:
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groups of cells
swelling of M, cell, organelles inflammation! Random & diffuse DNA degeneration plasma membrane smoothing |
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apoptosis characteristics:
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single cells - shrinkage
blebbed plasma membrane - phosphatidyl serine clumped and fragmented chromatin (pyknosis) apoptotic bodies |
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heat shock proteins
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protein chaperons (ubiquitin) aid the correct folding of proteins in response to heat, cold, stress (oxidative or reductive).
examples = HSP90 cardiovascular and HSP70 immunity |
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Effects of inc temp on cells
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+ thermal movement, HSP produced, protein coagulation, cell death, membrane defects and
depolymerisation of the mitotic spindle |
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Effects of dec temp on cells
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- termal movement, HSP produced, metabolic processes retarted, ICICLES = freeze/ thaw. cell death
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Activation of apoptosis (4)
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DNA damage (PARP -> AIF)
mitochondrial malformation Caspases Death ligands (Fas / TNF) |
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Activation of necrosis
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cell membrane damage...
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Damage to DNA synthesis possibly results in... (4)
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point mutation, chromosomal breaks (addition, deletion, rearrangement), cross links, mitosis defects
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Photobleaching effect
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irreversible decomposition of fluorochromes due to interactions with molecular oxygen. Light induces the excited state required for the reaction.
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human body cells that can autoflouresce?
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myoglobin
retinal cells - rhodopsin haemoglobin |
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Name 5 components of a flourescence microscope
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Light source - UV/Blue/Green
Excitation filter (only excitated light) objective lens dichromatic mirror Emmision filter (only emitted light) |
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Advantages of laser confocal M over flourescence M (4)
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1- more sensitive
2- 3D reconstruction 3- no photobleaching 4- signal to noise ration is better |
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Principle of Agar diffusion?
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substance placed in the middle of an agar plate with cell culture spread evenly on it.
Cell death is proportional to the toxicity of the substance in a circle arrangement as the substance diffuses out and kills the cells |
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Role of mitochondria in apoptosis?
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Bcl-2 proteins on M membrane surface
+ permeability, cytochrome C released, APAF + ATP = apoptosome. |
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define a gene
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a specific length of dna that codes for a protein or rna
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explain the term FRAP
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"flourescent recover after photobleaching" - proves the fluid mosaic model of the bilipid membrane. Damaged proteins are replaced with fuctional ones via membrane diffusion.
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Extrinisc pathway of apoptosis (basic)
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Fas ligand -> FADD -> procaspase 8 -> caspase 3 etc...
FADD = Fas associated death domain (intracellular process) |
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what is REACH?
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registration, evaluation, authorisation and restriction of chemicals
aim is to improve protection of human health and environment. EU chemicals industry 2006 |
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what is a terminator?
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a dna sequence at the end of a gene operon used to terminate transcription.
Rhoe factor or intrinsic hairpin loop |
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What kind of dna is in mitochondria?
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circular, not associated with histones, maternal origin in humans.
mtDNA though to derive from bacteria which were englufed by eukaryotic cells. |
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what is the osmolarity of human plasma?
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290 mOsm/kg
mili-osmoles per kg |
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three phases of cell culturing?
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lag, log, plateau phase
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three chemicals in cyropreservation
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glycerol
polyethyleneglycol dimethyl sulfoxide |
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what is a cell strain?
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it is a subline or clone of the original cell line.
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what is HeLa?
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Henretta lacks cervical cancer, continuous cell line.
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primary culture?
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dissaggregation of cells and placed on a cultivation surface (Eagles MEM)
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Enzymatic disaggregation of cells?
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Trypsin, EDTA, collagenase
ethylenediamine tetraacetic acid |
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secondary culture?
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PC dispersed in cell suspension and reseeded into fresh vessels = passage
Cell line produced. |
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Fate of cell lines?
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normal= growth and death (lag, log, plateau)
Cell strain= selected by cloning, subline of original cell line produced Continuous cell line = transformation invitro |
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What is a stem cell line?
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A continous cell line (SC transform invitro) with stem cell properties to still differentiate.
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Explain histiotypic culture...
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Cells are reaggregated in suspension then infiltrated onto a 3D tissue like structure matrix.
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Explain organotypic culture
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reassociation of cells from DIFFERENT lineage. (many cells make up a tissue, many tissues make up an organ)
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What is a hybridoma?
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a hybrid cell resulting from the fusion of a lymphocyte and a tumor cell; used to culture a specific monoclonal antibody.
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advantages of tissue culture?
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precise control of physiologic conditions
better biological standardisation of experiements cyropreservation = years of work on the same cell line invitro culture = cheaper than animals no ethical and legal problems |
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disadvantages of cell tissue cultures
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cells dissociated from 3D geometry and ECM = loss of cell interactions
lack homeostatic mechanisms that you would find invivo. PCC are not stable due to overgrowth or dedifferentiation. |
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five types of bio-modelling?
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computer programs
3D models cell cultures laboratory animals human volunteers |
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Explain FRAME
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fund for the replacement of animals in medical experiments
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what is a xenobiotic?
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a chemical found in an organism which is not normally produced or expected to be present.
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How did we induce cell death (necrosis) in paramecium?
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eosin
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cell culture environment includes what? (4)
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substrate, culture medium, gas phase, temperature
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what is hayflick's limit?
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is the number of times a normal cell population will divide before it stops, presumably because the telomeres shorten to a critical length.
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Two main constitutes of culitvation medium?
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Eagles MEM (minimum essential medium)
Bovine/calf SERA (serumalbumin) 10%: contains a wide range of minor components which effect cell growth |
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Explain conditions for the GAS PHASE of culture experiments
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5% CO2 with Ph at 7.4, in equilibrium with sodium bicarbonate in the medium
Organ culutures require 95% O2 |
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What signs of a cell culture show it needs a medium change?
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A Ph drop below 6.5
Morphological deterioration - nucleus granulates, vacuolisation of the cytoplasm, rounding up of cells. |
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what is the 3R concept?
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Refinement, reduction and replacement
of laboratory animals with other toxicological testing methods. = invitro mammalian cells. |
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Name three "targets" of measurement to asses proliferation in a cytotoxicity test.
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Cell protein count (coomasie blue test)
DNA count ATP / ADP ratio (best one) - ratio is constant in proliferating / live cells |
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Give an example of a metabolic activity - cytotoxic test
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Viable cells reduce TETRAZOLIUM salts (MTS/MTT) to coloured FORMAZEN compounds.
Focus is on bio functions inside intact cells. |
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Give an example of four cytotoxicity methods.
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Viability - Trypan blue
Proliferation - ATP/ADP ratio Metabolic assay - tetrazolium -> formazen DNA chips / microassays- gene expression level determined |
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How do DNA chips / microassays work?
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DNA sequences are applied to a slide / nitrocellulose membrane.
DNA's are used to probe target sequences. the effects of a toxicant increases or decreases the level of gene expression. |
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what were we testing when we used Iodonal B? What is its active ingredient?
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cell viability and the compound was iodophor
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Which three things are most desirable in microscopy?
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Magnification - magnified image of the specimen
Resolution - separate the details Contrast - to make the details visible |
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Focus length and resolution of human eye?
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10cm and 0.1mm
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Microscope magnification & resolution?
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1000x and 0.2um (micrometers)
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Why cant you increase the magnification of a LM beyond 1000x?
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The resolution would not improve rendering the image blurry
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Why is oil immersion sometimes used.
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It creates a continuous film between the coverslip and the lens so light rays do not refract away.
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What kind of microscope do we use?
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NIKON SE COMPOUND LIGHT MICROSCOPE
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what is the numerical aperture at 10x?
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10X = 0.25 NA
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what is the numerical aperture at 40x?
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0.65 NA
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what is the numerical aperture at 100x?
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1.30 NA
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Describe bright field microscopy
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Sample illumination is transmitted, via objective to be viewed from above
several objective lenses limited resolution dark image on clear background |
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What does "parafocal principle" mean?
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When an object is in focus with the course adjustment knob it will still be in focus at all other magnifications.
corresponding focal points in the same plane |
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what does "paracentral principle" mean?
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the object must be in the center of the field of view before increasing the magnification, or it will be left out.
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what is the "field of view"?
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the circle of light you see when you look into the microscope. Inc Mag = smaller FOV
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What is the condenser and how does it affect resolution and contrast?
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condenser ensures that all parts of the specimen are evenly lit via the iris diaphragm.
inc light = + resolution / poor contrast dec light = + contrast / poor resolution |
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what are the "vernier scales"?
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the vertical and horizontal readings on the mechanical stage of the M.
used to find the same spot on a slide. |
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If at 1000x, 10 cells fit in the FOV what size are they?
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18um
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If 30 cells fit in your FOV at 400x what is the cell diamter?
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15um
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FOV diameter at 100x?
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1.8mm
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FOV diameter at 1000x?
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180um
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FOV diameter at 40x?
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450um
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size estimation is what?
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field of view (mm or mm)
divided by estimated no of cells in transect of FOV. |
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Explain what "phase contrast" means
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The PC-M exploits interference effects that take place when two types of light recombine.
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What is numerica aperture?
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it is a dimensionless number characterising the number of angles of which a system can accept or emit light. inc mag = + NA
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what is Dark Field microscopy?
Differential / Normaski M uses the same principle |
DF-M is a technique used to increase the contrast of unstained transparent specimens.
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Phase contrast other details
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the phase annulus (clear) must match the phase plate (darker)
phase differences of light passing through an object are converted to the changes in intensity (amplitude) |
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How is the best phase contrast achieved?
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one has to shift the phase of light by 1/4 lambda in the +/- sense.
high refractive index = darker |
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What kind of light is used in phase contrast microscopy
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monochromatic yellow-green light which is most sensitive to our eyes.
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what is a telomere?
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it is a length of repetitive DNA at the 3' end of the chromosome with a TTAGGG sequence.
It protects coding genes from shortening which occurs during mitosis |
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what is CAAT?
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the "center for alternatives to animal experimentation"
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what is overtons rule?
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Increases lipid solubility of a molecule increases its diffusion rate across a plasma membrane.
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when does haemolysis occur?
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when red blood cells are placed in a hypotonic solution.
cell swelling and burst. |
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what makes the fluid mosaic model unique?
singer & nicolson 1972 |
the dynamic interspersed relationship between the phospholipid bilayer and membrane proteins (integral and peripheral)
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which part of the plasma membrane confers antigenic specificity to the cell
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carbohydrate chains from integral glycoproteins.
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what is the thickness / are the basic functions of the plasmamembrane?
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7.5nm (nanometers).
surrounds protoplasm and regulates which substances enter and exit the cell. |
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define osmosis
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the diffusion of water across a membrane in response to a concentration gradient
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what will be the result if a plant cell is placed in a hypertonic solution?
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plasmolysis - water leaves the cell by osmosis, plasma membrane shrinks away from the cell wall.
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define hypertonic solution
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The concentration of solute in an external solution is greater than that of inside a cell.
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define a hypotonic solution
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The concentraion of solute in an external solution is lower than that of inside a cell.
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Four characteristics of continuous cell lines.
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- loss of contact inhibition
- "imortal" - transformed invitro / tumour derived - dedifferentiation. |
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Four characteristics of primary cell lines.
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- diploid karyotype
- terminal differentiation - contact inhibition of growth & proliferation - senesence and death |
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Structure and function of aquaporins
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six transmembrane alpha helices in circular fomation create a selective water pore which regulates water inflow to a cell.
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what happens if you place a red blood cell in a hypertonic solution?
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crenation / plasmolysis as water moves out of the cell by osmosis.
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give six examples of INTRACELLULAR movement
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-cytoplasmic streaming (cyclosis due to actin microfilaments)
-vesicle trafficing between vesicles and cell surface - cell division for cytokinesis - movement of chromosomes in mitosis - pigment movement for colouration - discharge of vesicle content |
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Genetic microtubule defects (3)
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anosmia (loss of olfaction
hyrdocephalus kartagner syndome (primary cillary dyskinesis) |
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aquired microtubule defects (3)
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-hydrocephalus (lack of vit D)
- cillary beat arrest (toxins, bacteria) - cancer |
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MOA of Taxol
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prevents dissasembly of microtubules
= mitotic arrest |
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MOA of nocodazole
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depolymerises the mitotic spindle
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MOA of colchicine
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inhibits microtubule polymerisation
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MOA of vinblastine, vincristine
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binds to tubulin preventing dynamic instability at both ends
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New sea sponge derived microtubule inhibitors
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Eribulin - prevents dynamic instability
Discodermolide - prevents depolymerization in the G2/M phase |
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what is kinesin?
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motorprotein which caries vesicles towards the + end of the microtubule.
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what is dynein?
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motorprotein which caries vesicles towards the - end of the microtubule
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what is a topoisomerase?
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an isomerase enzyme that acts on the unwinding or overwinding of DNA in 3D space.
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what are topoisomerase inhibitors?
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drugs which prevent unwinding of DNA during replication = damaged replication (quinolones)
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what does permeability of a molecule depend on throug a PM?
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size, charge, concentration, solubility
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name 5 online information sources
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EBESCO
pubmed nature.com science direct medscape |
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during A mitochondira release
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Diablo / smac
AIF cytochrome C endopeptidase G |
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what is the photochemical effect?
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When light hits phototoxic compounds inside the cell
eosin / porphyrin |
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what is porphyria?
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it is a rare genetic disease characterised by dysfunction of heme metabolism and deposition of porphyrins in teeth, skin and bones.
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Two ways of DNA isolation?
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phenol based
phenol free |
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what is PDT?
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PHOTODYNAMIC THERAPY
- a photosensitizer is exposed to a group of cells. - when light is shone on the area, the cells react with molecular oxygen and initiate apoptosis/ necrosis. cancer: light wavelengths and PS are specific to each other! |
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basically describe the phenol based extraction of DNA
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transfer of nucleic acid into a water phase of a solution. Removal of acid associated proteins and lipids in phase separation.
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How would you dissociate DNA/RNA in a cell?
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Degredation via mechanical force- chemicals- then enzymes:
Proteinase K or PRONASE or detergent solutions. |
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What are the best conditions for enzyme digestion of cells to extract DNA?
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37*C with proteinase k or pronase
left over night. |
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what does SDS stand for?
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sodium dodecyl sulfate - emulsifies lipids and enables the dissociation of DNA and proteins (the histone complex)
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What does EDTA stand for and what does it do?
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ethylenediaminetetraacetic acid
deactivates metal dependant enzymes and DNA associated ions by chelating the metal ions. |
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what is the ideal PH for DNA extraction?
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pH 8
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which buffer is used to keep the pH (8) stable during extraction.
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TRIS - buffer capacity of 6.5 -> 9.7
trishydroxymethylaminomethane |
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What is PCR?
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polymerase chain reaction, used to exponentially amplify DNA with the use of primers and polymerase enzymes. (in vitro method)
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what is a DNA dipstick?
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a kit used for measuing nucleic acid concentration and yield
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what is NONIDET solution?
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it is a solution used in DNA extraction to breakdown membranosus structures
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what is IF?
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impact factor -
it is a measure of citations to science journals, a proxy for the importance of a journal to its field. |
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Give an example of:
positive taxis Negative taxis |
plants growing towards light
protective reflex (hand withdrawl) |
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define kinesis
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Reflex - LIKE - activity.
stimulus = change in speed/direction away from noxious stimulus. |
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when a cell exhibits ameboid movement name the four changes of actin-PM interactions.
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stress fibers, ruffling membrane, lamellipodia, filopodia
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Describe the motility seen in Euglena
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positive phototaxis as a result of photoreceptors at the base of the flagellum (microtubule movement)
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What is depth of field in microscopy?
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The area infront and behind of the specimen that will be in the acceptable area
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Define the mechanism and occurance of bioluminescence
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A biochemical oxidative process that results in the release of energy as emitted light.
Luciferin + molecular oxygen catylased by luciferase. |
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In the DNA isolation practical which two solutions were used?
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EDTA
Sodium dodecyl sulphate |
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Which of the following represent molecular motor proteins?
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A. Gelsolin
B. Myosin + C. Kinesin + D. Actin E. Dynamin + |
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What is gelsolin?
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Gelsolin is an actin-binding protein that is a key regulator of actin filament assembly and disassembly.
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What is wiskott-aldrich syndrome?
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An X-linked recessive genetic disease characterised by thrombocytopenia (lack of platelets)
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What is a chaperone protein?
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Chaperone proteins aid in the non-convalent folding or unfolding of other macromolecules
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What is YFP?
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yellow flourescent protein
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Cyclosis is an example of movement of...
Which is based on... we observed the phenomenon in.... |
cyctoplasmic streaming
actin microfilaments Elodea |
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Monoclonal antibodies are formed from?
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hybridomas
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Hybridomas arise from?
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B lymphocytes fused with tumour cells
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Applications of monoclonal antibodies?
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immunohistochemistry diagnostic tests
cancer treatment, for specific cancer antigens |
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Transfusion of pt occured with DISTILLED WATER (in a rush) what is the main consequence?
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RBC's are hypertonic relative to pure water and will burst undergoing haemolysis
serious possibly fatal |
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FRAP means and is used for?
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flourescence recovery after photobleaching. It is used to study the fluid mosaic model of plasma membranes with integral and peripheral membrane proteins
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GIve three examples of human cells which use locomotion
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macrophages - ameboid movement
neurons - growth cones mesenchymal cells - cell crawling (mesenchymal movement) with MT help (4 things there) |
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The most famous model organism for apoptotic studies is..
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C. Elegans 1030 cells and 131 undergo apoptosis.
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what are stress fibers?
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high order structures in the cell containing actin fillaments, myosin motor proteins and crosslinking proteins. Support the cell and have a role in movement
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What is PEG
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polyethylene glycol
A polyether used in cyropreservation |
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Define totipotency
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Cells which are totipotent can differentiate into any cell of the body including the extraembryonic tissues. The zygote is the only source of totipotent cells.
all plant cells are totipotent |
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FAS
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is a transmembrane protein related to the Tumour Necrosis Factor family. (it is a receptor) Binding results in the extrinsic pathway of apoptosis.
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In agar diffusion testing of cell viability what is the dye used called?
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Neutral Red
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MOA of vinblastine
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prevents depolymerisation of the microtubules
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What does stoke shift mean?
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It is the difference in wavelength between excitation wl and emission wl.
Emission is always longer than the excitation (energy lost...) |
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Rough emission spectra wavelenths for colours
blue green red |
B: 420-500
G: 510-560 R: 590- 650 |
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promidium iodide stains what?
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intercalates with DNA - red
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ethidium bromide stains what?
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intercalates with DNA - orange
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Clinical dissorders associated with aquaporins?
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diabetes insipidus, cataracts of the cornea, cirrhosis (liver inc AQ)
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what is a bibliographic record?
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A record of an article or book in a database, it includes info about authors, sources and an abstract
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What is botulinum toxin?
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It is a microtubular poison preventing the transmission of signals at the neuromuscular junction. Produced by a bacterium
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what is crenation?
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osmotic responce to RBC's being placed in a hypertonic solution - cell shrinkage
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As magnification increases....
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Numerical aperture increases
Field of view decreases Depth of field decreases |
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Give an example of a light source for flourescence microscopy...
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xenon arc lamp
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how does a dichromatic mirror work?
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It reflects wavelenghts shorther than a specific wavelenght and passes light longer than a specific wavelength
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where does the word caspase come from?
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Caspase cleaves cysteine/aspartate amide bonds = C-ASPA -ase = enzyme..
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what is ex vivo?
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Tissue taken from invivo, processed in a lab and then pub back invivo
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name THREE cultivation mediums
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fibroblast growth medium
melanocyte medium CADMEX growth medium EAGLES MEM growth medium |
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Name five essentials for cell culturing!
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incubator, laminar hood flow, fridge & freezer, autoclave (sterilizer), inverted microscope, water purification unit, liquid handelling devices.
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what is the purpose of an inverted microscope?
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to see cell cultures at the bottom of conical flasks, light source and condenser above the sample with the objective below the sample to the lenses.
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why do RBC's undergo haemolysis whilst in an isotonic solution?
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because the solution is isotonic to a certain ION, all other ions are thus in an "unbalenced" state in relation to RBC's
Hence we use ISOIONIC solution (ringers) which is specific for RBC's |
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Where do we use Monoclonal Antibodies in medicine?
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1 - IHC for cell staining or radiotherapy
2- Tumour marker diagnostics 3- Differential diagnostics of viral, bacterial, parasitic infections. |
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what is PCR?
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polymerase chain reaction
it is a method to exponentially amplify DNA invitro using DNA polymerases and primers (variable temp) Denaturation, Annealing, Extension & repeat.... |
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what is flow cyctometry?
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A technique used to count & examine microscopic particles in cells / chromosomes > suspended in fluid stream and detected by electronic device by light penetration.
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what is filliopodia?
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cytoplasmic projections of plasmamembrane in a migrating cell containing bundles of microfilaments.
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what is an enhancer?
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it is a region of DNA that can bind proteins to enchance trascription of genes
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Agar diffusion principle is a test of what? How does it work?
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cytotoxicity test on cell viability:
effect of substance on bacteria growth culture. |
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define passage
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primary culture dissaggregated and reseeded into a fresh vessel
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confocal lens characteristics:
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laser / photomultiplier / pinhole filter
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Epiflourescent lens characteristics:
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xenon arc lamp / ocular detection / diaphragmatic filter.
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phosphorescence
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emission of light persists after the excitation by light
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epi-flourescence
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light ot the objective illuminates the specimen and emission light is reabsorbed by the objective to the lenses
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dichromatic mirror
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efficiently reflects shorter wavelengths of light and efficiently passes longer wavelengths of light (emission)
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stokes law
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difference in wavelength between excitation and emission spectra
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what is quenching?
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FRET - flourescence resonance energy transfer - the excited flurophore excites the other molecules around it = other cellular interactions
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light sources for flourescence microscopy>
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xenon arc lamp
mercury arc lamp argon ion laser |
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what is CBS
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chromatic beam splitter (dichomatic mirror)
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light budget is what?
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3.6x 10^4 photons are emitted before destruction of the flurophore (with molecular oxygen)
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what is CCD?
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charge coupled device- used to enchance quantum efficiency for detecting emission
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what is TRIF?
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total internal reflection flourescence - it decreases detector noise and enhances the optical background
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give three examples of physiologically occuring apoptosis
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1- development of the embryo- formation of all tubular structures
2- homeostasis: postitive and negative selection of B + T lymphocytes inthe thymus 3- deletion of damaged and dangerous cells (DNA damaged) |
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what is porphyria?
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it is a hetergeneous group of inherited disorders of haem biosynthesis
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what are the three most common presenting symptoms of porphyria?
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cutaneous lesions, neuropsychiatric disorder, acute abdominal pain.
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How would you diagnose porphyria?>
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urine test for increased
1- aminolaevulinic acid 2- porphobilinogen |
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What is the treatment for porphyria?
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Avoid risk factors - sunlight/ alcohol/ illicit drugs
haem arginate and glucose (attack) chloroquinine (inc porphyrin excretion in urine) |
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What is the volume of water in a 70kg human body?
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42L
65% intracellular 35% ECM |
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What does AQP mean?
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aquaporin protein
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what is GLP?
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aquaglyceroporin
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what is NDI?
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nephrogenic diabetes insipidis
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what does one osmole mean?
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The ammount of substance which dissociates in solution to form one mole of osmotically active particles
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when do you find and decrease in AQP2?
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1 - diabetes inspidius
2 - renal failure 3 - water loading |
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when do you find an increase in AQP2?
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1 - thirst
2 - pregnancy 3 - cirrhosis of the liver |
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Which type of aquaporin is present in the kidney collecting duct?
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AQP2 regulated by ADH (antidiuretic hormone)
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in what phase of the cell cycle do microtubule inhibitors most likely arrest the process?
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G2/M phase
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what is NLP?
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natural language processing -
it converts information from computers into human language (speech / syntax) |
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what is text mining?
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Automatic extraction of information about genes, proteins
bioNLP = natural language processing about biological data |
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what is PMID?
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the unique identification number of a pubmed citation.
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