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CTB
CTB Cards
233
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Professional
01/20/2009

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Term
Hematoxylin
Definition
Basic positively charged blue dye that stains mainly in the nucleus b/c binds to acidic negatively charged DNA
Term
Eosin
Definition
Acidic negatively charged red dye that stains mainly in the cytoplasm b/c binds to mostly positive proteins
Term
Schiff reagent
Definition
Special stain used to stain DNA or glycogen
Term
Sudan dyes
Definition
Lipophilic stains
Term
Histochemistry
Definition
Also known as cytochemistry. Tracks active enzymes in tissue b/c the active enzyme in a fixed tissue catalyzes the formation of a dense black reactive product.
Term
Succinic Dehydrogenase
Definition
marks red muscle fibers
Term
Immunochemistry
Definition
Uses antibodies to detect specific proteins or other antigens.
Term
flourescein
Definition
flourescent reporter molecule used in immunochemistry
Term
rhodamine
Definition
flourescent reporter molecule used in immunochemistry
Term
Autoradiography
Definition
Detects a specific cellular activity like DNA or Protein synthesis using a radioactive substance to label cells ie radioactive then dna synth
Term
H-thymidine
Definition
used to label the nucleus during dna synthesis in autoradiography
Term
Intestinal Crypts
Definition
site of stem cells that replenish cells lining the intestine
Term
Fluorescent In Situ Hybridization
Definition
detects specific RNA or DNA sequences based on complimentary pairing
Term
Confocal Microscopy
Definition
uses laser light to excite flourescent probes eliminating light scatter and providing superior resolution
Term
electron Microscopy
Definition
Permits high resolution, high magnification ultrastructural views of cells
Term
Osmium
Definition
stain used in EM
Term
Transmission EM
Definition
obtains sectional EM view
Term
Scanning EM
Definition
get 3-D surface image
Term
Freeze Fracture
Definition
special EM technique utilizing liquid nitrogen to quick freeze cells which are then cracked and observed using TEM. Useful for studying hydrophobic interior of phospholipid bilayers
Term
E-face
Definition
half of bilayer associated with outside of cell using freeze fracture
Term
P face
Definition
half of bilayer associated with the cytoplasm using freeze fracture
Term
Tissue preparation steps
Definition
1. Fixation 2. Dehydration 3. Clearing
4. Embedding 5. Sectioning 6. Staining
Term
Ultrastructure
Definition
refers to structure of the cell seen with EM
Term
Nuclear matrix def and 3 components
Definition
non-random infrastructure of nucleus consisting of
1.Nuclear envelope/pore complex/lamina
2.Nucleolus
3.Internal Nuclear Matrix
Term
nuclear envelope
Definition
double membrane that separates cytoplasm from chromatin that is continuous with the ER
Term
Function of the nuclear matrix
Definition
1. Framework of nucleus
2. Organizes the genomic DNA into domains to regulate gene expression and cell replication
Term
Outer Nuclear Membrane
Definition
faces cytoplasm and contains ribosomes
Term
Inner Nuclear membrane
Definition
faces the cytoplasm and has integral proteins to bind the nuclear lamina which in turn binds marginal heterochromatin
Term
width of nuclear pores
Definition
10 nm
Term
Pore import into the nucleus
Definition
only proteins
Term
Nuclear pore export
Definition
only mRNA,rRNA and proteins
Term
Nucleoporins
Definition
nuclear pore proteins
Term
Nuclear localization signals
Definition
sequence with positively charged AA like lysine and arginine contained in proteins that target the protein to dock on nucleoporins for nuclear import
Term
Importin
Definition
heterodimer containing alpha and beta subunits that mediates protein import
Term
cytoplasmic masking protein
Definition
protein that blocks recognition of nuclear bound proteins by importin that must be phosphorylated to enter the nucleus
Term
Nuclear Export sequence
Definition
short leucine rich sequences that target proteins for nuclear export
Term
Exportins
Definition
analagous to importins; facilitate export of proteins and rna from the nucleus
Term
Progeria
Definition
early aging disease caused by defective splicing of Lamin A
Term
3 disease caused by LMNA mutant gene
Definition
muscular dystrophy
cardiomyopathy
progeria
Term
Nucleolus
Definition
site of rRna production through RNA pol 1 and 3 and RNA large and small subunit assembly (note individual subunit assembly occurs here, subunits stay separate and later assemble in the nucleus)
Term
Does nucleolus have a membrane
Definition
no
Term
Percentage of euchromatin that is active
Definition
10
Term
Function on internal nuclear matrix
Definition
confers non random order to the chromatin
Term
Barr body
Definition
inactive X chromosome that is always situated along the inner nuclear membrane
Term
3 traits of pluripotent embryonic stem cell
Definition
1. Lots of chromosome mobility
2. Lots of gene txn
3. little repressed heterochromatin
note-all 3 become decreased as cell differentiates
Term
3 big traits of nuclear matrix
Definition
1. confers non random order
2 NM proteins are tissue specific
3. NM organizes the txn and replication of Dna
Term
Replicon
Definition
group of sequences that dna is replicated in that are contained in the nuclear matrix
Term
growth factors that activate the cell cycle
Definition
FGFs, IGFs, Wnts
Term
growth factors that inhibit the cell cycle
Definition
TGFbeta
Term
External factors of cell cycle regulation
Definition
growth factors, cytokines, and hormones
Term
internal factors of cell cycle regulation
Definition
early response genes (myc,fos), and delayed response genes (cdks and cyclins)
Term
CDK subunit
Definition
catalytic subunit in which the level in the cell stays constant during the cell cycle
Term
Cyclin Subunit
Definition
regulatory subunit whose level increases during the cell cycle
Term
Cyclin D binds to
Definition
CDK 4
Term
Cyclin E and A bind to
Definition
CDK 2
Term
Cyclin B binds to
Definition
CDK 1
Term
Retinoblastoma (RB)
Definition
Tumor suppressor gene bound to E2F-1 that releases its hold when phosphorylated by Cyclin D-CDK4 heterodimer
Term
What activates the genes for cyclins E and A?
Definition
E2F-1
Term
What overcomes the restriction point that keeps the cell cycle in G1?
Definition
Cyclin E/CDK2
Term
What mediates DNA replication during the S phase of the cell cycle?
Definition
Cyclin A/CDK2
Term
What activates m-phase?
Definition
cyclin B/cdk1
Term
What dephosphorylates cyclin B-CDK1
Definition
cdc25
Term
What activates anaphase?
Definition
Anaphase Promoter Complex (APC) which contains ubiquitin
Term
Traits of cancer
Definition
1. loss of cellular differentiation
2. increased proliferation and invasiveness of cells
3.changes in chromosomes: rearrangement, loss or gain
Term
5 gene categories mutated in cancer
Definition
1. Proto-oncogenes
2. Tumor suppresor genes
3. Apoptosis regulating genes
4. Telomerase
5. Genes that repair DNA
Term
Proto-oncogenes
Definition
genes that encode the proteins that activate the cell cycle including cell surface receptors, second messengers, txn factors, cyclins and cdks.
Term
oncogenes
Definition
mutated proto-oncogenes that activate the cell-cycle
Term
ras
Definition
GTP binding protein that functions as a proto-oncogene
Term
src
Definition
tyrosine kinase cell surface receptor that is proto-oncogene
Term
Examples of oncogenes
Definition
ras, src, cyclin D, EGFR b/c mutation activates them and the cell cycle
Term
Tumor supressor genes
Definition
genes that inhibit the cell cycle including p21, p53, Rb, and BRCA
Term
p21
Definition
inhibits cdks 2 and 4
Term
p51
Definition
mutated in 50% of cancers and has 3 major roles
1. sentinel of the genome
2. activates p21
3. directly ignites apoptosis
Term
Rb
Definition
binds E2F1
Term
BRCA
Definition
mutated in breast cancer
Term
bcl-2
Definition
anti-apoptotic factor that when mutated can become abnormally active resulting in b-cell lymphoma
Term
TNF
Definition
tumor necrosis factor that binds to the TNF receptor on cell membrane and checks the balance of pro and anti-apoptotic factors in the cell.
Term
Pro-apoptotic signals induce... resulting in...
Definition
Outer mitochondrial membrane leakiness resulting in cytochrome C escape to the cytoplasm
Term
Effect of cytochrome C escape to the cytoplasm
Definition
results in activation of Caspase, protease that destroys the cell organelles, and subsequent defoliation of the cell resulting in apoptosis
Term
What releases TNF?
Definition
Macrophage
Term
Telomere
Definition
highly repetive DNA of approximately 15000 bp in length on the end of hte chromosomes
Term
Telomerase
Definition
enzyme active in stem cells and cancer cells that restores telomeres to their normal length after each cell division
Term
3 ways to target cancer
Definition
1. Target metastasis
2. Target angiogenesis
3. Target specific sick molecules
Term
Role of protease in metastasis
Definition
proteases especially metalloproteases facilitate metastatic spread of cancer by enabling them to eat through the ECM
Term
TIMPS
Definition
tissue inhibitors of metalloproteinases
-antimetastatic treatment
Term
What enzyme cleaves dsRNA into siRNA?
Definition
dicer
Term
siRNAs complex with what enzyme
Definition
RISC
Term
Two types of antimolecular cancer therapy
Definition
Monoclonal antibodies (rituxan for B cell non hodgkins lymphoma) and siRNA
Term
In what phase is the centrosome duplicated
Definition
G2
Term
In what phase are histones synthesized
Definition
S
Term
In what phase does the hyperphosphorylation of histones and non histone proteins occur?
Definition
G2
Term
Mutation in EGFR causes
Definition
non small cell lung carcinoma
Term
taxol
Definition
drug stabilizing microtubules blocking cell division
Term
MTOC
Definition
microtubule organizing center which in cells is the centrosome
Term
Polarity of MT in bipolar spindle apparatus
Definition
+ end always faces away from the MTOC
Term
Gamma tubulin ring complex
Definition
large multiprotein complex containing gamma tubulin that is involved in the initiation of microtubule polymerization at MTOCs. The ring caps - end of MT preventing disassembly.
Term
Axoneme
Definition
cytoskeletal component of the cilium or flagellum with a characteristic 9+2 pattern of MT (central pair of singlet MT and 9 outer doublet)that arises from basal bodies
Term
Basal bodies
Definition
centrioles at the cell surface consisting of triplet mictrotubules that form the base of cilia and flagella
Term
Ciliary bending
Definition
relative sliding of the microtubles in the axoneme mediated by the molecular motor dynein
Term
Dynein/kinesin
Definition
ATPase motility motors that use microtubules as tracks
Term
What direction does kinesin travel
Definition
always toward the + end
Term
What direction does dynein travel?
Definition
always toward - end
Term
Dynein/Kinesin structure
Definition
Two ATPase head domains move across MT using a cross-bridge like cycle.
Term
Processivity of Dynein and kinesin
Definition
Very processive, one of the two heads is always attached to the MT at a given time.
Term
Fast axonal transport of vesicles
Definition
MT mediated motility in which kinesin moves a vesicle down the axon (toward +)and dynein moves it back toward the cell body (toward the -).
Term
Role of motor proteins in mitosis
Definition
Help to move the MT to mediate the movements of the chromosomes toward the poles and split the cells
Term
cytoskeleton
Definition
organized intracellular network of three classes of protein filaments:
1. IF
2. MT
3. Actin MF
Term
IF form from
Definition
intermediate fibrous proteins
Term
MT form from
Definition
tubulin
Term
MF form from
Definition
actin
Term
IF function (general)
Definition
1. cradle nucleus
2. provide mechanical strength
Term
MF function (general)
Definition
1. cell movements
2. distribution of components at cell surface
Term
IF location of greatest concention
Definition
cells under mechanical stress
Term
Cytoskeletal element in desmosomal intracellular junctions
Definition
IF
Term
IF size
Definition
10 nm
Term
MF size
Definition
5-9 nm
Term
MT size
Definition
25 nm
Term
Types of IF
Definition
1.Nuclear Lamins
2. vimentin
3.GFAP
4.Keratins
5.NF
Term
Sarcomas are
Definition
Vimentin +
Term
Keratin + disorder
Definition
Breast and GI primary cancers
Term
Diagnostic value of IF
Definition
important clinically for distinguishing btwn epithelial, mesenchymal and neuronal derived tumors
Term
Emery-Dreifuss Muscular Dystrophy
Definition
Autosomal Dominant mutation of gene encoding lamins A and C
Term
Defective keratin means
Definition
skin epithelium highly susceptible to mechanical stress ie blistering of the skin
Term
epidermolysis bullosa simplex
Definition
excess blistering due to defective keratin
Term
Structural similarities and differences in IFs
Definition
Conserved alpha helical domains but N and C terminus ends are variable
Term
Role of alpha helical domain in IF
Definition
allow fibers to bond there to form dimers and tetramers
Term
Role of N and C terminus in IF
Definition
functional diversity
Term
Main cytoskeleton is composed of
Definition
IF cytoskeleton
Term
In nondividing cells, what is the status of IF
Definition
1-5% of subunits exist in a free pool and can exchange with the IF cytoskeleton
Term
Assembly of subunits of IF
Definition
Soluble IF monomers assemble into dimers and form staggered antiparallel tetramers. These pack to form a nonpolarized high tensile insoluble fiber (ie stable and lacking dynamics of others)
Term
polarity of IF
Definition
none
Term
polarity in MT
Definition
yes
Term
polarity in MF
Definition
yes
Term
Assembly of IF subunits mediated by
Definition
phos and dephosphorylation
Term
How does G actin get to F actin
Definition
binds ATP and polymerizes
Term
What favors the stability of f-actin
Definition
atp cap
Term
MT treadmilling?
Definition
yes
Term
IF treadmilling?
Definition
no
Term
MF treadmilling?
Definition
yes
Term
Treadmilling: If both ends of F actin are exposed, p0lymerization will proceed until
Definition
Conc. of free monomers is above critical Conc for + end and below critical Conc for - end so net assembly and disassembly are =
Term
Polymerization of MF in cells
Definition
favored b/c free actin pool is 1000 times higher than critical concentration of .1 microm. so actin binding proteins help to keep level lower so cell doesn't gel up
Term
cytochalasin
Definition
disrupts actin by depolymerizing F actin through binding to + end.
Term
phalloidin
Definition
stabilizes f actin by locking subunits together
Term
Types of ABP (actin binding proteins)?
Definition
1. Regulation
2. Severing
3. X linking
4. Motor
Term
Role and ex of regulatory of ABP?
Definition
Keep free actin pool low so cell doesn't gel up.
ex
1. thymosin beta4
2. profilin
3. tropomodulin
4. capping protein
Term
Role of Severing ABP and ex
Definition
sever F actin chains
ex
ADF/cofilin and gelsolin
Term
Role and ex of x linking ABP
Definition
have two actin binding sites separated by divergent intervening sequences in which they generate parallel and orthogonal actin arrays. (Ca2+ inhibits actin binding)
ex
spectrin,
dystrophin,
filamin,
alpha actinin,
fimbrin
Term
Motor ABP
Definition
myosin
Term
Stress fibers?
Definition
loosely packed contractile bundles of F actin that permit intercalation of myosin thick filaments for fibroblast contraction of connective tissue during wound healing
Term
Microvilli structure
Definition
tight parallel bundles of MF form the core
Term
Actin's role in regulating cytoplasmic fluidity?
Definition
orthogonal cross-linking produces actin gel that regulates fluidity
Term
Duchenne muscular dystrophy
Definition
mutated dystrophin is not able to bind to cortical F actin resulting in cell membrane ruptures and muscle cell degeneration
Term
What is often used to link the cytoskeleton to the ECM?
Definition
Actin
Term
Myosin Atpases
Definition
associate with actin filaments for movement of vesicles or cell membrane protrusions
Term
Amoeboid movement (dendritic nucleation model)
Definition
protruding edge of a crawling cell extends through dynamic assembly/disassembly of actin filaments in a branching network
Term
Wiskott-Aldrich syndrome
Definition
defective phagocytosis due to inability to form actin based lamellipodia because of mutation in membrane protein that Arp2/3 binds to
Term
Arp2/3
Definition
ABP that binds to surface receptor W to mediate phagocytosis or amoeboid movement
Term
Bacteria movement can be mediated by
Definition
utilization of ARP complex to form actin filament that polymerizes to mediate transport
Term
Describe mechanism of orthagonal crosslinking mediation of clotting and ABP involved
Definition
filamin anchors forming actin network via a glycoprotein bound to a fibrous clot
Term
Which cell has a very high nucleus to cytoplasm ratio?
Definition
Lymphocyte
Term
What cells lack a nucleus?
Definition
RBC (erythrocyte)
Term
What cells are multinucleated?
Definition
skeletal muscle
Term
What cells have a multilobed nucleus?
Definition
Neutrophil
Term
Eosinophils have what type of nucleus?
Definition
Bilobed
Term
Is euchromatin electron lucent?
Definition
Yes it will show up as lightly stained
Term
Is heterochormatin electron lucent?
Definition
No, electron dense so stains dark.
Term
What is contained in the electron lucent central portion of the nucleolus?
Definition
The tips of ten chormosomes called the nucleolar organizer.
Term
Pars Fibrosa
Definition
electron dense portion of the nucleolus in which the rRNA is undergoing txn
Term
Pars granulosa
Definition
granular component of the nucleolus consisting of ribonuclear protein representing the nascent ribosomes
Term
Why do cancer and embryonic cell have well developed nucleoluses
Definition
Need lots of txn for cell growth and function as well as ribosomes to make proteins
Term
Is it possible for a human cell to have more than one nucleolus?
Definition
yes
Term
what organelle is usually located near the centrosome?
Definition
Golgi
Term
Name two symptoms of immotile cilia syndrome?
Definition
Infertility, chronic sinusitis, and bronchitis
Term
Function of MAPs
Definition
bind microtubules to
1.stabilize them
2.link them to other cytoskeletal parts
3.Facilitate their interaction with other organelles
Term
Terminal web
Definition
Actin MF, spectrin, and IF form a cytoskeletal cortex just deep to the PM that help maintains cell shape
Term
Name some locations of cells that may have microvilli?
Definition
GI or urinary tracts ie places with a lumen
Term
Where in the body would you find ciliated epithelial cells?
Definition
Respiratory and reproductive (oviduct) tracts
Term
Glycocalyx
Definition
Cell coat that covers the external surface of all cells with oligo and polysaccharide chains linked to PM proteins and lipids
Term
What are the functions of the glycocalyx?
Definition
Cell recognition, intercellular, absorption of molecules to cell surface, mechanical and chemical protection
Term
Basal Lamina
Definition
extracellular material referred to as the basement membrane
Term
Functions of basal lamina
Definition
provides structural support and serves as a barrier to materials that may pass between epithelium and connective tissue
Term
Zonula Occludens
Definition
Tight junction which is a mesh-like band that encircles apical ends of lateral plasma membranes that practically eliminates intracellular space btwn the cells
Term
Describe the staining of zonula occludens
Definition
Pentalaminar (dark,light,dark,light,dark)
ie
o==oo==o
Term
Function of zonula occludens
Definition
blocks passage of luminal contents btwn cells
Term
List tissues in which zonula occludens btwn adjacent cells is necessary for proper function
Definition
Blood brain layer, intestinal epithelium, urinary bladder, kidney
Term
What are the three types of cell junctions?
Definition
occluding, adhering, and communicating
Term
Types of occluding junction
Definition
zonula occludens (tight junctions)
Term
Types of adhering junctions
Definition
Zonula adherens, Desmosomes (macula adherens), and hemidesmosomes
Term
Types of communicating junctions
Definition
Gap Junctions (Nexus Junctions)
Term
Zonula Adherens
Definition
belt-like band that encircles epithelial cells just deep to the zonula occludens
Term
What is bound to integral membrane proteins using linking proteins to form an e- dense plaque at the cytoplasmic face of the membrane junction?
Definition
actin
Term
In zonula adherens what do the extracellular domain of the glycoproteins bind homophilically with?
Definition
calcium
Term
Desmosomes
Definition
or macula adherens are focal cell-cell adhesion sites which integrate the cytoskeletons of adjacent cells
Term
Desmoplakins
Definition
cytoplasmic proteins that form e- dense plaques just beneath the plasma membranes
in desmosomes
Term
Band 6
Definition
cytoplasmic proteins that form e- dense plaques just beneath the plasma membranes
in desmosomes
Term
Fibers that form e- dense gaps at base of desmosomes
Definition
IF
Term
Width of desmosome
Definition
30 nm
Term
Desmosome gap is bridged by transmembrane glycoproteins called
Definition
cadherins (family of cell adhesion molecules)
Term
Desmoglein and desmocollins
Definition
cadherins like
Term
Desmosomes join
Definition
cell to cell
Term
Hemidesmosomes join
Definition
cell to basal laminae
Term
What fibers are involved in hemidesmosomes?
Definition
IF
Term
BP230 and plectin
Definition
cytoplasmic plaque proteins in hemidesmosomes
Term
BP180 and integrin
Definition
transmembrane proteins in hemidesmosomes
Term
This type of collagen provides additional linkage to ECM from hemidesmosomes?
Definition
Collagen 7
Term
In what tissues would you expect to find numerous adhering junctions?
Definition
Cardiac and skeletal muscle due to mechanical stress
Term
Symptom of Pemphigus vulgaris and bullous pemphigus
Definition
blistering
Term
Autoimmune diseases that affect desmosomes and hemidesmosomes
Definition
Pemphigus vulgaris and bullous pemphigus
Term
Bullous pemphigus antigen
Definition
BP180
Term
Pemphigus vulgaris antigen
Definition
Desmogleins 1 and 3
Term
Junctions that allow cells to be electrically and metabolically coupled
Definition
Gap junctions
Term
Distance across Gap junction
Definition
3nm
Term
Transmembrane proteins involved in gap junctions
Definition
connexons
Term
Advantages of electrically coupled cells?
Definition
instantaneous signal propagation ie synchronous
Term
Are ribosomes found in the nucleus
Definition
no subunits are assembled in the cytoplasm
Term
The membrane of the ER is continuous with the membrane of what?
Definition
Nucleus (nuclear envelope)
Term
Function of Golgi apparatus
Definition
glycosylation of proteins and protein targeting
Term
four post-translation process that take place in the lumen of the rER
Definition
core glycosylation, disulfide bond formation, polypeptide folding, and subunit assembly
Term
Source of secretory vesicles and granules
Definition
golgi
Term
Primary lysosomes
Definition
small, membrane bound vesicles, homogenously filled with e- dense contents
Term
Secondary lysosome
Definition
heterogenous lysosome that is made when a primary lysosome fuses with an endosome
Term
Exocytosis
Definition
vesicular release into ECM
Term
Endocytosis
Definition
process by which molecules are take into a cell
Term
Cristae
Definition
folds of the IMM
Term
Mitochondrial matrix
Definition
area enclosed by IMM
Term
Lamellar mitochondria
Definition
have cristae arrange in shelf-like layers
Term
Tubulovesicular mitochondria/cristae
Definition
Mitochondria with an extensively folded IMM that looks like short tubules or vesicles surround by the OMM
Term
Where are tubovesicular mitochondria commonly found?
Definition
steroid producing cells
Term
What is the advantage of a tubovesicular mitochondria?
Definition
increased surface area so more steroid producing enzymes are housed since steroids are produced on demand need lots of enzymes to accomodate rapid synthesis
Term
Fibers that bind lipid droplets
Definition
IF
Term
Name two organelles w/ double membranes?
Definition
nucleus and mito
Term
This appears as electron dense rosettes free in cytoplasm
Definition
glycogen
Term
Spherocytosis
Definition
genetic defect in cytoskeletal components that changes the normal shape of rbc's
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