MCB 2210: FINAL EXAM

CourseStructure object (196412) - University Of Connecticut

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320 Cards in this Set

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Functions of ABPs	Control of Polymerizationand Depolymerization monomer sequestering proteins nucleating factors capping proteins stabilizing proteins depolymerizing proteins severing proteins Organization of filaments cross-linking proteins bundling proteins membrane linker proteins Movement of…
Capping Proteins	Stabilize filaments by binding to ends CapZ - caps (+) ends tropomodulin - caps (-) ends
Stabilizing Proteins	bind along lengths of filaments stabilize polymerized state
Cross-linkng Proteins	two actin binding domains separated by spacer domains filamin, dystrophin, spectrin
Bundling Proteins	Cross-linking proteins with short spacers
Membrane-actin Linker Proteins	attach the actin cytoskeleton to the plasma membrane ERM Proteins: linker between F-actin and the integral membrane proteins Spectrin: actin to membrane proteins
Functions of MAPs	Control of Polymerizationand Depolymerization oligomer sequestering proteins nucleating factors end-binding (+TIP) proteins stabilizing proteins depolymerizing proteins severing proteins Organization of microtublues cross-linking proteins bundling proteins membrane linker protei…
Tubulin oligomer binding proteins	Stathmin binds tubulin heterodimers or oligomers and promotes catastrophe and depolymerization
Nucleating Proteins	λ-TURC nucleates MT assembly at the centromere
End binding proteins	+TIPs bind to the (+) ends of of MTs EB1 is a +TIP that can regulate (+) end dynamics
Severing Proteins	Katanin severs MTs and may promote depolymerization at (-) ends
Depolymerizing Proteins	Subset of kinesins promote MT depolymerization at the (+) end by binding and inducing protofilament curling
Polymer-binding MAPs	stabilize Mts by binding to sides enhance assembly by stabilizing nuclei organize MTs into bundles mediate MT interactions with other proteins two-major domains microtubule binding projection MAP2 and Tau organizing microtubules in neuronal axons and dendrites
Structural Features of Actin	binds ATP or ADP complexed with Mg2+ monomer: G-actin, filamentous: F-actin F-actin: helical polymer of G-actin subunits held together by non-covalent interactions polar pointed end (-) barbed end (+) different dynamic properties of ends`
Study of Actin Assembly	In vitro: initiated by salts into a solution of G-actin assembly and disassembly properties of pure actin are different from those for actin in the cell
Actin Assembly Kinetics	3 steps nucleation: formation of a stable seed enlongation: growth steady state: no net increase or decrease in amount of polymerized actin
Critical Concentration	Concentration of free actin at the steady state of the system if concentration is above Cc then subunits will add
Concept of Critical Concentration	ATP hydrolysis accompanies polymerization two ends of actin filament have different critical concentrations
Treadmilling	flux of actin subunits through the filament
Steady state	active treadmilling, but no net growth or shrinkage
Actin Binding Proteins	control assembly and disassembly
Actin Sequestering Proteins	bind monomers of G-actin to prevent polymerization Thymosin β4 profilin
Phalloidin	prevents filament depolymerization
Cytochalasin	Caps (+) end and prevents elongation; eventual depolymerization
Latrunculin	binds actin monomers and prevents them from polymerizing into filaments (sequestration); rapid disassembly of actin filaments
Formin (actin nucleator)	generate long unbranched filaments; facilitates (+) end growth while remaining attached to (+) end
Tandem actin monomer-binding proteins	nucleate unbranched filaments
Arp2/3 Complex	only actin nucleator to create branched filaments works in conjunction with WASP family WASP+Arp2/3 Complex have nucleating activity (-) end capped by Arp2/3
Actin nucleators	control cell shape, movement, and division during health and disease
Carcinoma	cancer of epithelial cells
Sarcomas	Cancer of connective or muscle tissues
Leukemias and Lymphomas	Cancer of blood cells
Characteristicsof Cancer	uncontrolled cell growth increased cell division decreased cell death enhanced cell migration
Cancer is caused by mutations in...	DNA repair cell signaling, cell cycle control cell growth programmed cell death cytoskeletal rearrangements tissue architecture
Cancer cells two heritable properties	reproduce in defiance of the normal restraints on cell growth and division invade and colonize territories normally reserved for other cells
Tumor	new growth; normal cell that grows and proliferates out of control
Benign	non-invasive
malignant	cells have acquired the ability to invade other tissues
Metastasis	Spread of cancer cells
Caretaker genes	encode proteins involved in DNA repair
Caretake genes contribute to cancer via:	Loss of Function
Proto-onocogenes contribute to cancer via:	Gain of Function
Tumor-suppressor genes contribute to cancer via:	Loss of Function
Tumor-suppressor genes	encode proteins that inhibit cell proliferation regulate or inhibit cell cycle progression receptors or signal transducers for hormones or developmental signals checkpoint control proteins that arrest the cell cycle p53: "the guardian of the genome" proteins that promote apoptosis e…
Unphosphorylated Rb	binds to E2F transcription factors to prevent activation of many genes required fro DNA synthesis
Phosphorylation Rb	releases E2F, thereby activating transcription of genes required for S-phase
Transformation	rounder and less adherent; grow while normal cells have become quiescent
Ras°	oncogene GTPase that controls signal transduction pathways that are activated by growth factors capable of transforming cells in culture or inducing cancer in animals called proto-onocgene
Multi-hit model for cancer induction	several events are required for carinogenesis
p53 "guardian of the genome"	cellular stress sensor and transcriptional regulator as p53 levels rise in cells causes undergo cell cycle arrest, apoptosis, or replicative cell senescence loss of function abolishes cell cycle (DNA damage) checkpoints responsible for more than half of human cancer
ATM	ATM-mediated phophorylation of p53 directly stabilizes p53
Mdm2	Mdm2 complexes with p53 causing p53 ubiquitination and degradation
HPV	express proteins that inactivate RB and p53
angiogenesis	growth of new blood vessels
Cancer Cell migration/metastasis	driven by actin cytoskeleton
Stem cell contribution to cancer	may contribute to the replenishment of malignant cells
Cancer Stem Cells	generate additional malignant stem cells; generate rapidly-dividing transit-amplifying cells
Cancer: Nuclear size	enlarged nuclei represent more aggressive metastatic disease
Invadopodia	protrusions that degrade ECM; actin-dependent
Cell adhesion molecules	cells adhere directly to one another
adhesion receptors	cell-matrix adhesion
ECM	proteins and polysaccharides secreted by cells into extracellular spaces
CAMs	generate tight adhesion when weak interactions are compbined
Cadherins	cross-bridges between adjacent cells
Integrins	adhesion receptors bind to large multi-adhesive matrix proteins such as fibronectin
catenins	cytoskeletal adapter protein that links cadherins to intracellular actin fialmanets
desmosoms	cadherins are linked indirectly to intermediate filaments
Tight junction	forms barriers that seal off body cavities; prevent diffusion of plasma membrane proteins between the apical and basolateral; prevent diffusion of macromolecules in the spaces between cells
Gap Junctions	gaps through which ions and small molecules (<1kDa) can pass
proteoglycans	glycoproteins that cushion cells
collagens	insoluable sheet-or-fiber forming proteins that provide structural integrity and mechanical strength; most abundant protein in connective tissues
fibronectin and laminin	cross-link adhesion receptors
basal lamina	thin (60-120nm) sheet-like meshwork of ECM components that underlies or surrounds many epithelial and non-epithelial tissues
Type IV Collagen	trimeric protein that forms a 2D network of fibers
Laminin	fibrous 2D network; binds to adhesion receptors
Connective tissues	volume made up of extracellular matrix, rather than cells
fibroblasts	most abundant cells in connective tissues
Collagen Structure	triple-helical polypeptides high abundance of glycine, proline, and hydroxyproline
Proteoglycans	secreted or surface-attached glycoproteins containing specialized polysaccharide chains called glyosaminoglycins (GAGs)
Glycosaminoglycans (GAGs)	long linear polymers of specific repeating disaccharides
Fibronectin	multiple domains for binding collagens, proteoglycans, and adhesion receptors organizing other components of the ECM regulating cell matrix adhesions shape and movement of cells organization of the actin cytoskeleton binds to integrins (tripeptide sequence: RGD)
Hemi-desmosomes	cause the stable attachment of the ventral cell surfaces to the ECM
Integrins	most prominent adhesion receptors
Cell Cycle	ordered series of events that leads to cell duplication and division
G1-phase	period between completion of previous mitosis and initiation of DNA synthesis for the next mitosis
G2-Phase	the period between the completion of DNA replication and initiation of mitosis
G0	Phase that cells are in if they exit the cell cycle
Post-translational modifications	phosphorylation of tyrosines, series, and threonines reversible ubiquitination of lysines protein degradations irreversible
PI 3-kinase Pathways	receptor tyrosine kinases (RTKs) recruit and activate PI 3-kinasses (PI3K) PI3K phosphorlyates the 3' position of inositols to generate PI(3,4,5)PS Activation of serene/threonine kinase (Akt) mTOR becomes activated phosphorylation of targets involving proteins synthesis and metabolism…
Protein Degradation Pathaways	Lysosome Proteasome
Proteasome	large macromolecular machine degrade many cellular proteins
3 Functions of Protein Degradation:	It removes proteins that are misfiled, damaged, or potentially toxic Controlled degradation of normal proteins provides a powerful mechanism to maintain appropriate levels of proteins Regulated degradation also permits rapid responses to changing conditions
Ubiquitin	Highly conserved 76 aa polypeptide that marks proteins for degradation by the proteasome
Poly-ubiquniation	multiple molecules of ubiquitin are attached to a molecule; recognized for degradation by the proteasome
E3 Ub-ligases	enzyme that achieves poly-ubiquination
cyclin	regulatory subunit
cyclin-dependent kinase (CDK)	catalytic subunit
Protein phosphatases and ubiquitin ligases	key regulators of the cell cycle transitions
Regulation of CDK	Activation by cyclin-binding and T-loop phosphorylation binding cyclin to CDK alters conformation of the T-loop 2. Inhibitory phosphorylation of the active site by Wee1 kinases - reduces activity of CDKs 3. De-phophorylation of these sites by Cdc25 phosphates 4. Physicial Inhibity by …
G1 cyclin-CDKs	transcription of genes required for DNA replication
SCF ubiquitin ligase	polyubiquitinates inhibitors of S-phase cyclin-CDKs
S-phase cyclin-CDKs	activate DNA replication origins
mitotic cyclin-CDKs	entry into mitosis
APC	polyubiquitinates securing and polyubiquitinates mitotic cyclins
Cdc14 phosphatase	promotes telophase
Cyclin B-CDK1	phosphorylates cellular proteins and causes changes for mitosis
Condensins	phosphorylization causes chromosome condensation
Nuclear lamins	phosphorylization causes nuclear breakdown
microtubule-associated proteins	phophorylization causes changes in microtubule dynamics
ER or Golgi associated proteins	phosphorylization causes reorganization of the ER and the Golgi
Checkpoint types	DNA-damage and spindle
Checkpoint purpose	ensure that one phase of the cell cycle is completed successfully before the cell is allowed to progress to the next phase
Checkpoint Mechanism	negative feedback mechanisms that block cell cycle progression allow time for correction or repair
Sensor proteins	detect abnormalities
Transducer proteins	relay or amplify the damage signal
effector proteins	halt cell cycle in response to damage
Anaphase Promoting Complex (APC)	triggers degradation of the cohesins that connect sister chromatids by a separate enzyme
APC Activity Mechanism	APC ubiquitinates securin causes the release of separase activity of separatase degrades cohesion
Mitosis/Maturation Promoting Factor (MPF)	low in interphase rises as cells enter mitosis
hfp://www.youtube.com/watch?v=6xMXKU7JnMQ&	Meiosis Self Study
Meiosis	one cycle of chromosome replication followed by two cycles of cell division to produce haploid germ cells
synapsis	pairing of chromosomes along lengths; allows for recombination between chromatids of homologous chromosomes occurs
Necrosis	premature death due to infection or injury
Apoptosis	programmed cell death
Autophagy	self-eating
Phagocytosis	involves one cell "eating" a dying cell
Telomeres	physical ends of linear chromosomes
Telomerase	reverse transcriptase enzyme that adds these telomere sequences to the ends of chromosomes and maintain 3-20kb of DNA repeats in humans
Senescence	withdrawal from the cell cycle and stop dividing
p53	becomes activated by telomere shortening and can trigger apoptosis
Apoptotic Cell Features	chromosome condensation at the nuclear periphery shrinking of the cell body blabbing of the cell membrane endonuclease cleavage flipping of phophatidylserine from the inner leaflet of the plasma membrane to the outer leaflet
Apoptosis Benefit	eliminating abnormal or misplaced cells during development in a quality control process elimination of cells that could be potentially dangerous, as self-reactive immune cells elimination of cells with the potential to cause cancer the killing of virus-infected cells by cytotoxic T cel…
caspases	intracellular machinery responsible for apoptosis is comprise of proteases
Intrinsic pathways to apoptosis	triggered from within a cell DNA damage hypoxia low nutrients lack of proper extracellular survival signal
Cytochrome C	Binds to proteins that activate procaspases
Extrinsic Pathways to Apoptosis	binding of extracellular signaling proteins to cell surface 'death' receptors
Autophagy	conserved intracellular pathway that controls protein and organelle degradation, and has key roles in development, survival and homeostasis
Autophagosome	double-membrane vacuole degradation of cytoplasmic components after fusion with lysosome
Integrins	physical link between the ECM and actin filaments
Stress Fibers	anchored to focal adhesions
Actin polymerization at the leading edge	coupled to membrane protrusion
Retrograde flow	network of filaments is thought to flux backwards
Steps of Membrane Mobility	first step involves the forward protrusion of the lamellipodium which is driven by the force of actin polymerization adhesion: lamellipodium interacts with the substrate; forms structures such as focal contacts cell body translocation: been postulated to occur via a dynamic network cont…
Dominant-negative (GDP-locked) versions of Cdc43, Rac, and Rho	inhibit cell migration
Signal Transduction	How signals are transmitted from the outside of the cell to the inside, allowing cells to modify behavior
Molecules that can cross the membrane directly	Hydrophobic signaling molecules steroid hormones receptor is in the cytoplasm or nucleus Nitric Oxide/Carbon Monoxide dissolved gas regulates many pathways
Molecules that cannot directly cross the membrane	hydrophilic
Signaling via chemical messengers	Autocrine, paracrine, and endocrine signaling cell surface receptor binds a molecule secreted by itself (autocrine) a nearby cell (paracrine) or a distant cell (endocrine)
Contact-dependent signaling	cell surface receptor binds a signal on the surface of another cell or on the extracellular matrix the cell is in contact with
Mechanism of signal transduction via membrane receptors	same signal can bind to multiple types of the receptor receptor can be coupled to multiple types of transducer second messengers can provide high signal amplification second messenger can be coupled to multiple effector types
Ligand gated channels	signal opens a channel - (ion pore)
G-protein coupled receptors	signal activates a G-protein
Enzyme-linked receptors	signal activates the enzymatic activity of the receptor (Usually a kinase)
Transmembrane Receptors	7 membrane spanning helices extracellular domain binds molecule signal transmit signal to cyptoplasmic domain TM receptors act as a GEF
Heterotrimeric G protein receives signal	Three different subunits two are tethered to the membrane by covalently linked lipids transmits signal to effector protein
Adenyl cyclase	Gα binds to adenyl cyclase activating it makes cAMP from ATP cAMP acts as second messenger cAMP binds to PKA causing inhibitory subunit to fall off kinase is now active and goes to nucleus phosphorylates nuclear proteins to change expression
Receptor Tyrosine Kinases	Usually signal pass transmembrane proteins binds ligand on the outside of the cell causes receptor to dimerize autophosphorylation of part of the cytoplasmic tail of the receptor phosphorylizaiton is always on tyrosine Both a ligand binding protein and a kinase that phosphorylates it…
G Proteins	control cellular processes like cell division and motility binds GTP or GDP GTPase activity that cleaves GTP to GDP Normally bound to GDP (off) Controlled by GEF, GAP, and GDI
GEF	causes GDP to be released and allows GTP to bind
GAP	stimulates the GTPase activity so that GTP is cleaved and activity turned off
GDI	prevents GDP from coming off keeping in the offs state
Metaphase	point when chromosomes become aligned in one plane halfway between two spindle poles
Anaphase	sister chromatids separate and are pulled forward by spindle poles by the kinteochore MTs
Anaphase A	the kinetochore MTs shorten and the chromosomes move toward the poles
Anaphase B	polar MTs elongate and the poles move farther apart
Spindle Assembly Checkpoint activation	kinetochores that are not attached to MTs kinetochores that are not under tension
CENP-E	Kin-N protein at the kinetochore that binds to the MT movement can be driven by depolymerization of the (+) end
Dynein Motors	located at the cell cortex participate in pulling the poles apart
Telophase	daughter chromosomes arrive at the poles nuclear envelope reformes chromatin begins to de-condense
Cytokinesis	cytoplasmic division by cleavage
contractile ring	draws plasma membrane in
midbody	remnant of the spindle
Contractile Ring in amoebae, fungi, and animals	centrally-positioned contractile ring of actin filaments and myosin II
Successful cytokinesis depends on:	placement of cleavage furrow contractile ring dynamics separation of the plasma membrane
Rho GTPases	active; mark the cleavage site around the equator
Intermediate Filaments basic Characteristics	10 nm in diameter very stable do not bind nucleotides non-polar withstand stretching forces
Intermediate Filament Structure	helical coiled rod domain form parallel dimer assemble in to antiparallel tetramer tetramer is basic building block no polarity
Types of Intermediate Filaments	Type I (acidic) and Type II (basic) keratins heteropolymers epithelial cells 2. Type III Vimentin and related filaments homopolymers most widely distributed intermediate filament protein 3. Type IV Neurofilaments heteropolymers found in axons 4. Nuclear Lamins meshwork of Ifs th…
Septins Characteristics	10 nm diameter bind and hydrolyze GTP cells with mutations arrest at cytokinesis important for contractile ring
Septin Structure	GTP-binding domain coiled coil
Functions of Septin Filaments	Cytokinesis: cleavage furrow and contractile ring Scaffolding Membrane trafficking: movement and fusion of membrane vesicles
Fibroblasts	cell of connective tissue
Lamellipodia	thin sheet-like structures
Filopodia	thin needle-like projections or spikes
Stress fibers	long cables of actin that function in cell adhesion and contraction
focal adhesion	attach the cell to the underlying substrates
Cell Theory	all living creatures are made of one or more cells the cell is the basic structural unit of living things cells can only arise by division from pre-existing cells
Basic Properties of Cells	composed of proteins, lipids, carbohydrates and nucleic acids high complexity encoding information in genes membranes reproduction acquire and utilize energy carry out chemical reactions carry out mechanical activities respond to stimuli self-regulation evolving
Central Dogma	DNA mRNA protein
Prokaryotes	lack a nucleus and internal membranes
Eukaryotes	have a nucleus and and extensive internal membrane system
Plasma Membrane	lipid bilayer
Cytoplasm	soluble internal contents of the cell
Nucleoid	area in which DNA is concentrated
Plasma Membrane Properties	selective permeability diffusion rates transporters
Passive Diffusion	molecules diffuse directly through the lipid bilayer
Passive Transport	down a concentration gradient; no energy beyond thermal motion
Active Transport	extra energy input for transport
Passive Transport 1	passage in either direction multipass transmembrane proteins ion specific regulated
K+ Channel	large channel selectivity filter at one end Fits K+ perfectly Na+ is too small in interact properly and sticks
Passive Transport 2: Carriers	no direct energy input mulipass membrane bidirectional reversible conformation change
Carrier: GLUT	12 transmembrane domains N and C intracellular termini affinity for glucose responds to insulin
Active Transporters	active transporters move against a chemical, electrical or electrochemical gradient
Primary active transporters	ATP-dependent pumps light driven pumps
Secondary active transporters	Symport moves 2 molecules in same direction Antiport moves 2 molecules in the opposite direction
ATP-dependent Pumps	Uses ATP energy to move one or more molecules v-type: does not become phosphorylated p-type: becomes phosphorylated from ATP during transport
Na+/K+ ATPase	3 Na+/2 K+
K+/K+ ATPases	Stomach acidification P-type
Ca++ ATPases	pump Ca out of the cell p-type
ABC Transporters	v-type isoforms important in cancer
Vesicular H+ ATPases	Acidification of lysosomes, golgi v-types
Secondary Active Transport	energy input needed moves one molecule against a gradient uses energy from an existing gradient Carrier Mediated: Protein changes conformation
Antiporters/Exchangers	two ions are moving in opposite directions molecule is moving down a concentration gradient one moving up a concentration gradient exchangers
Action Potentials Characteristics	all-or-none encode information by the frequency of action potential
Steps of Action Potential	Na+ channel in dendrite senses depolarization Na+ channel opens membrane depolarizes K+ channels open Na+ channels inactivate Membrane returns to -70mV
Membrane Functions	separate compartments provide scaffold mediate interactions signal transduction
Components of biological Membranes:	Lipids cholesterol proteins
Miscelles	small sphere with tails pointed in
Bilayers	Two layers of lipid with tails pointed toward each other
Flourescence recovery after photobleaching (FRAP)	label phospholipids with a fluorescent probe shine a bright laser on a small spot of membrane to bleach it measure how long it takes for fluorescent molecules to diffuse back into the region
Flipases	membrane proteins flip-flop the lipids back to normal sides
Lipid Rafts	Areas with high concentrations of certain lipids and proteins
Protein Primary Structure	sequence of amino acids
Protein Secondary Structure	local shape
Protein Tertiary Structure	3D shape
Protein Quaternary Structure	multi-subunit assemblies
Functional Domain	acts as a unit but is part of a protein
Kd	Higher Kd: lower affinity Lower Kd: higher affinity
Integral membrane protien	interact directly with the lipid portion of the bilayer
Lipid anchored proteins	covalent addition of a lipid to a protein targets the lipoprotein to the membrane
Peripheral membrane proteins	attached to the membrane via interactions with other membrane proteins, not lipids
Structure of Transmembrane region of proteins	hydrophobic/ amphipathic alpha helix or amphipathic beta sheet hydrophilic regions face inwards of the transporter
Beta-barrels	hydrophobic are outward polar are inside forms a pore through the membrane that is hydrophilic
Cell Fusion	measures protein mobility label proteins of one cell with red dye label proteins of second cell with green dye fuse cells to form a heterokaryon watch what happens
Primary Cells	non-cancerous, non-transformed cells
Transformed Cells	cancerous cells
Light microscopy limitations	magnification, contrast, and resolving power
Magnification	amount you blow up the initial image dependent on lens
Resolution	how far apart tow objects have to be to be seen as two separate objects not related to magnification determined by wavelength of light properties of lens
Fluoresence	molecule absorbs one wavelength of light and admits alone
Immunocytochemistry	Immunofluorescence
Techniques involving antibodies	immunoblotting immunoprecipitation immunoisolation
Transfection	infecting cells with foreign DNA to cause a foreign protein to be expressed in a cell
Transmission electron microscope (TEM)	images electrons that pass through a thin specimen
Scanning Electron Microscope (SEM)	images electrons scattered by an intact object
Microtubule Structure	polymer of tubulin subunits form a cylindrical filaments formed from α and β tubulin heterodimers both bind GTP α - irreversably β - hydrolyzes GTP to GDP 13 protofilaments polar (-) embedded in the MT organizing center (MTOC or centrosome)
GTP Cap	stabilizes (+) end of MT to prevent depolymerization
Taxol	binds to MTs and stabilizes the polymer preventing disassembly
Cholchicine	prevents further depolymerization not the MT end
Nocodazole	binds to tubulin subunits and triggers MT depolymerization
Pericentrioloar Material (PCM)	microtubules emerge from PCM near the centrioles of the centrosome
γ-TURC	anchors MTs at the MTOC/centrosome
γ-tubulin	microtubule nucleator
Mitosis	process of chromosome segregation
M Phase Subcellular changes	chromosome condensation: organized by histones, compacted by condensing mitotic spindle assembly: aligns the replicated chromosomes in a plane that bisects the cell, moved by spindle microtubules to opposite spindle poles Formation of the contractile ring: actin filaments and myosin II …
Prophase	Two centrosomes separate each centrosome forms radial MTs called an aster asters move apart
Pro-metaphse	nuclear envelope breakdown MTs are captured by kinetochores chromosomes move back and for the between the pole
Nuclear envelope breakdown	disassembly of the nuclear lamina cytoskeleton
congression	bi-directional movement of chromosomes near the equator of the spindle during pro-metaphase
Metaphase	point when chromosomes become aligned in one plane halfway between the two spindle poles
Myosin motor proteins	couple energy from ATP hydrolysis to conformational changes; myosins are (+) ended motors
Myosin Structure	Head: motor, actin binding ATPase activities neck: regulatory tail: determine properties
Myosin-Actin Cross-bridge Cycle	rigor state ATP binding ATP hydrolysis Pi release power stroke ADP release
Kin-N Kinesins	motor domain at the n-terminus; move to the (+) end
Kin-C Kinesins	motor domain at the c-terminus; move to (-) ends
Kin-I Kinesins	Internal motor domain; promote protofilament peeling
Conventional Kinesin	two heavy chains two light chains head neck tail light chains mediate interaction of Kinesin with membrane vesicles
Processive movement	movement over long distances without dissociating
Dyneins	mechanochemical enzymes that couple the energy from ATP hydrolysis to (-) end directed movements along MTs
Dynactin Complex	mediates the attachment of Dynein to vesicles and organelles critical for the function of cytoplasmic Dynein
Methods of Viral Entry	fusing with the plasma membrane endocytic-based mechanisms both require microtubules after entry
normal flora	commensal microbes
pathogens	organisms that can caused overt disease in healthy people
virulence factors	proteins that contribute to the ability of an organism to cause disease
Pathogenic Strategies and Virulence Factors	colonize multiply evade host response cause damage spread
Types of Virulence Factors:	Toxins: released, alter or disrupt normal processes Adhesins and/or invasins: on surface; promote attachment or entry into cells Secretion systems: translocate (inject proteins from bacteria into host cells Effectors: transolcated proteins that alter or disrupt normal processes within …
AB toxins	(A) Subunit: enzymatic (B) Subunit: cell-binding
Invasion	process of induced-cellular uptake
invasin	strucural similarites to fibronectin and binds to β1-integrins to promote actin cytoskeletal rearragements and enter cells
internalin	binds to E-cadherin to promote actin cytoskeletal rearrangements and internalization
effector proteins	trigger actin cytoskeletal rearrangements that result in bacterial invasion
Zipper and Trigger	mechanisms for pathogen-induced phagocytosis both require the polymerization of actin
vacuole escape	Listeria and Shigella
Prevention of Lysomal Maturation	Mycobacterium tuberculosis, salmonella, Legionella pneumophila, and Chlamydia trachomatis
Growth within lysosomes	Coxiella Burnetii
ER Functions	site of membrane and secretory protein synthesis Ca++ storage site of lipid synthesis detoxifying enzymes in liver cells
ER Structure	Rough smooth
Protein insertion into ER	co-translationally
Protein Targeting to the ER	proteins destined for membrane compartments or secretion are targeted initially to the ER
Chaperone Proteins	in ER lumen aid in folding
Fibroblasts	migration (actin)
osteoblasts	collagen secretion
neuronal cells	axonal trafficking (MTs, motors)
Muscle cells	sarcomeres and contraction (Actin and myosin)
Macrophages	extravasation
T-cells, B-cells, Antigen presenting cells	immunologicalsynapses (actin)
Respiratory epithelia, sperm	motile cilia and flagella (MTs, motors)
sensory cells	non-motile cilia - primary cilia (MTs, motors)
Sarcomere	thin and thick filaments actin filaments and actin-binding proteins myosin II motors
leukocytes	cross from the blood into tissues in response to chemical signals called chemoattractants that are released by other cells or by pathogens
selectin receptors	leukocytes can attach loosely to endothelial cells
extvasation	leukocyte's shape changes dramatically and it migrates between endothelial cells into the underlying tissue
Immunologicaly synapse (IS)	focal point for exocytosis, endocytosis, and signaling at a physical junction between lymphocytes
cilia	tiny hair like appendages with an arrangement of MTs at their core
axoneme	core consists of an array of microtubules and associated proteins
totipotency	ability of a single cell to divide and produce all the differentiated cells in an organism
somatic cells	cell that forms the body of a multicelluar organism
differentiation	process by which a less-specialized cell becomes a more-specialized cell
stem cells	undifferentiated cells that can reproduce themselves and also give rise to diverse specialized cell types
Pluripotent stem cell	can differentiate into any adult cell type
Multipotent stem cells	limited number of lineages
terminally differentiated cells	cells that are considered to be permanently committed to a specific function
Stem cells	characterized by the property of self-renwal and the capacity for differentiation; indefinite supply of fresh differentiated cells where these are lost, discarded, or needed in greater numbers
epidermis	epithelium that is self-repairing and continually renewed
Hematopoetic stem cells (HSCs)	found in bone marrow, peripheral blood, and umbilical cord blood
autologous transplants	patients receive their own stem cells
allogeneic transplants	patients receive stem cells from their brother, sister, or parent
nuclear reprogramming	switch in nuclear gene expression from one kind of somatic cell to that of an embryo or other cell type
Induced Pluripotency	expression of the four transcription factors Oct4, Sox2, Klf4, and c-Myc can reprogram somatic cells to a state that is similar to that of embryonic stem cells
Nuclear transfer to eggs	somatic cell nucleus is transplanted to an enucleated X.laevis (or mammalian) egg


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MCB 2210: FINAL EXAM

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