Term
| What does the removal of the signal sequence prior to transport do to the protein targeting? |
|
Definition
| It abolishes organelle targeting; remains in the cytosol. |
|
|
Term
| Where are the proteins found that lack a signal sequence? |
|
Definition
|
|
Term
| What is needed in order to correctly target a protein to a specific organ? |
|
Definition
|
|
Term
| Protein signal sequences are ___ and ___. |
|
Definition
|
|
Term
| The nuclear DNA is enclosed by a double-membrane called the ____. |
|
Definition
|
|
Term
| The outer nuclear membrane is continuous with the ____. |
|
Definition
|
|
Term
| What is the nuclear membrane supported by a meshwork of protein filaments that line the inner face of the membrane called? |
|
Definition
|
|
Term
| What perforates the nuclear envelope and acts as gates to regulate/select the material transported in and out of the nucleus? |
|
Definition
|
|
Term
| Protein traffic through the nuclear pores is ____. |
|
Definition
|
|
Term
| What do eukaryotic cells use to separate antagonistic molecular events? |
|
Definition
| Intracellular organelles (ex. separate protein synthesis from protein degredation) |
|
|
Term
| What is a membrane bound compartment that supports the bidirectional transport of material specialized to carry out a particular function called? |
|
Definition
|
|
Term
| Name two objects in the cell that are not organelles. |
|
Definition
|
|
Term
| What organelle in the eukaryotic cell contains many metabolic pathways and is the site for protein synthesis? |
|
Definition
|
|
Term
| What organelle in the eukaryotic cell contains main genome and is the site of DNA and RNA synthesis? |
|
Definition
|
|
Term
| What organelle in the eukaryotic cell synthesizes most of the lipids and proteins for distribution? |
|
Definition
|
|
Term
| What organelle in the eukaryotic cell modifies, sorts, and packages proteins and lipid for secretion or delivery to other organelles? |
|
Definition
|
|
Term
| What organelle in the eukaryotic cell is the site for intracellular degradation? |
|
Definition
|
|
Term
| What organelle in the eukaryotic cell is the site for sorting of endocytosed material? |
|
Definition
|
|
Term
| What organelle in the eukaryotic cell is the site for ATP synthesis by oxidative phosphorylation? |
|
Definition
|
|
Term
| What organelle in the eukaryotic cell is the site for ATP synthesis and carbon fixation by photosynthesis? |
|
Definition
|
|
Term
| What organelle in the eukaryotic cell is the site of oxidation of toxic molecules? |
|
Definition
|
|
Term
| Intracellular positioning, location, and function of organelles are all dependent on what? |
|
Definition
| Their attachment to the cytoskeleton |
|
|
Term
| How much of the eukaryotic cell volume do intracellular organelles compose? |
|
Definition
|
|
Term
| The amount of membrane associated with the ER is ____ that of the plasma membrane? |
|
Definition
|
|
Term
| The formation of intracellular compartments occurred in ____. |
|
Definition
|
|
Term
| The ___ and the ___ are the first intracellular compartments that form. |
|
Definition
|
|
Term
| The single DNA in prokaryotes is attached to the ___. |
|
Definition
|
|
Term
| In bacteria, what carries out all membrane dependent functions? |
|
Definition
|
|
Term
| The nucleus, ER, golgi, and lysosomes gave rise due to what? |
|
Definition
| early plasma membrane invagination |
|
|
Term
| The nucleus, ER, golgi, lysosomes, and their membranes are called what? |
|
Definition
|
|
Term
| What are the three mechanisms for protein transport? |
|
Definition
Gated - into and out of nucleus
Transmembrane - from cytosol to ER, mitochondria, chloroplast, and peroxisomes
Vesicular - from ER into the Golgi, lysosome and plasma membrane |
|
|
Term
| What type of protein transport involves the movement of proteins into and out of the nucleus? |
|
Definition
|
|
Term
| What type of protein transport involves the movement of proteins from the cytosol into the ER, the mitochondria, the chloroplast, and the peroxisome? |
|
Definition
|
|
Term
| What type of protein transport involves the movement of proteins from the ER into the Golgi, lysosome, and the plasma membrane? |
|
Definition
|
|
Term
| What must happen to the proteins being transported into the mitochondria, peroxisomes, chloroplast, and ER (transmembrane)? |
|
Definition
| Must be unfolded for entry |
|
|
Term
| What must happen to the proteins transported from the ER into the Golgi, lysosome, and plasma membrane (vesicular)? |
|
Definition
| Must be folded/assembled during transport. |
|
|
Term
| What must happen to gated transported proteins? |
|
Definition
|
|
Term
| 99% of the proteins synthesized in a eukaryotic cell begin where? |
|
Definition
| on free cytoplasmic ribosomes (exceptions: proteins made by mitochondria/chloroplast) |
|
|
Term
| Where does the bulk of translation occur? |
|
Definition
|
|
Term
| What are the three characteristics of sorting signals? |
|
Definition
15-60 amino acids long
Removed after transport (except nuclear transported proteins)
Conserved properties (charge, structure, hydrophobicity) |
|
|
Term
| Who discovered sorting signals? |
|
Definition
| Gunter Blobel (Nobel Prize 1999) |
|
|
Term
| What are the two types of nuclear transport? |
|
Definition
|
|
Term
| What size proteins can passively transport through the nucleus? |
|
Definition
|
|
Term
| What type of energy is required for gated protein transport in and out of the nucleus? |
|
Definition
|
|
Term
| What type of nuclear transport is needed for mRNA? |
|
Definition
|
|
Term
| What type of nuclear transport is needed for small metabolites? |
|
Definition
|
|
Term
| How much of the total membrane in an animal cell is made up by the ER? |
|
Definition
|
|
Term
| The ER is the ____ of the secretory pathway. |
|
Definition
|
|
Term
| How many different proteins make up the nuclear pore complex (NPC)? |
|
Definition
|
|
Term
| What is the signal sequence called that is contained by proteins recognized by the NPC and directs proteins from the cytosol into the nucleus? |
|
Definition
| Nuclear Localization Signal (NLS) |
|
|
Term
| What amino acids make up the Nuclear Localization Signal and what charge do they hold? |
|
Definition
Arginine and Lysine
Positive |
|
|
Term
| What happens to the NLS after transport? |
|
Definition
| It is NOT removed from the protein. |
|
|
Term
| What are proteins with an NLS recognized by? |
|
Definition
| Cytosolic nuclear transport receptor |
|
|
Term
| What is the GTP binding protein? |
|
Definition
| Ran (key for nuclear transport) |
|
|
Term
| Where is Ran-GTP located? |
|
Definition
|
|
Term
| Where is Ran-GDP located? |
|
Definition
|
|
Term
| What is the role of GTP in nuclear transport? |
|
Definition
1. Ran-GTP binds to incoming receptors with their attached cargo and promotes cargo release into the nucleus.
2. Ran-GTP escorts the receptor back to the cytosol
3. Ran-GTP is hydrolyzed to Ran-GDP promoting the release of the transport receptor. |
|
|
Term
| What is the driving force behind nuclear transport? |
|
Definition
| Differential subcellular localization of Ran-GTP and Ran-GDP |
|
|
Term
| What controls the differences in Ran? |
|
Definition
| Differential localization of Ran-GAP and Ran-GEF |
|
|
Term
| What promotes the hydrolysis of GTP to GDP and is located in the cytosol? |
|
Definition
| Ran-GAP (guanine activating protein) |
|
|
Term
| What promotes the exchange of GDP for GTP and is located in the nucleus? |
|
Definition
| Ran-GEF (Guanine exchange factor) |
|
|
Term
| For a multiprotein complex, how many proteins are needed to have a NLS for efficient nuclear targeting? |
|
Definition
|
|
Term
| Proteins that are transported into and out of the nucleus are ___ and often assembled into a ____ protein complex. |
|
Definition
|
|
Term
| Proteins that are selectively exported from the nucleus also have a targeting signal called a _____. |
|
Definition
| Nuclear Export Signal (NES) |
|
|
Term
| What is the first step in getting proteins integrated into the plasma membrane? |
|
Definition
| trafficking through the ER |
|
|
Term
|
Definition
Histones
DNA/RNA polymerases
DNA repair enzymes
DNA modifying enzymes(helicase, ligase)
Transcription factors (TFIID, TFIIH)
Repressors
RNA processing enzymes |
|
|
Term
| What are the two pools of ribosomes? |
|
Definition
Ribosomes bound to ER
Free Ribosomes
(actually no difference) |
|
|
Term
| How does translation occur if the mRNA codes for protein destined for the mitochondria, cytosol, chloroplast, nucleus, or peroxisome? |
|
Definition
| Ribosome translats mRNA in the cytosol. These proteins are targeted to their subcellular destination after complete translation (post-translational transport) |
|
|
Term
| How does translation occur if the mRNA codes for a protein with an ER targeting signal? |
|
Definition
| After 20-30 a.a. translate, the polypeptide chain is recognized by SRP (signal recognition particle). SRP binds to the signal sequence and the ribosome pauses translation (co-translational) |
|
|
Term
| What happens to the ER-bound ribosomes after they complete translation? |
|
Definition
| They are released into the cytosol. |
|
|
Term
| What is the only difference between the two pools of ribosomes (bound and free) |
|
Definition
| the protein they are making at any time |
|
|
Term
| What are the six characteristics of ER targeting sequences? |
|
Definition
1. Found at amino terminus (except multispanning proteins containing internal signals)
2. 20-30 amino acids in length
3. no a.a. sequence conservation
4. Contains 8 or more hydrophobic a.a.
5. Sig sequence removed after transport
6. Plays a role in ER targeting via SRP recognition and opening the ER translocation channel for passage |
|
|
Term
| What are the two types of proteins that are targeted to the ER? |
|
Definition
Soluble Proteins-completely translocated; single sorting signal
Transmembrane Proteins-partially translocated; multiple sorting signal |
|
|
Term
| Which proteins are polypeptide chains that completely translocated through the ER translocation channel for release into the lumen of the ER? |
|
Definition
|
|
Term
| Which proteins are polypeptide chains that partially translocate through the ER translocation channel for insertion into the ER membrane? |
|
Definition
|
|
Term
| What type of transport moves things out of the ER? |
|
Definition
|
|
Term
| What enzyme cleaves the signal sequence from the protein once in the ER? |
|
Definition
|
|
Term
| What is traffic outwards from the ER to the plasma membrane called? |
|
Definition
|
|
Term
| What is traffic inwards from the plasma membrane to the lysosome called? |
|
Definition
|
|
Term
| Endocytosis and Exocytosis are transported via ______ transport |
|
Definition
|
|
Term
| What three requirements must be met in order for vesicular transport to work? |
|
Definition
Select appropriate cargo for transport
Bud off of an organelle compartment
Fuse to the correct target membrane |
|
|
Term
| What is the protein layer called that forms on the cytosolic side of buds from a membrane? |
|
Definition
|
|
Term
| Coat proteins are specific to what two things? |
|
Definition
origin of formation
destination of resulting vesicle (delivery place) |
|
|
Term
| What are the two functions of the coat proteins? |
|
Definition
shape the membrane into a bud
help select molecules for transport (dont directly select) |
|
|
Term
| What are the best studied vesicles formed by? |
|
Definition
|
|
Term
| Which proteins link coat proteins to the vesicle membrane and selects the vesicle cargo by interacting with specific cargo receptors? |
|
Definition
|
|
Term
| What are transmembrane proteins that capture soluble cargo for packaging into the transport vesicle (select what will become cargo)? |
|
Definition
|
|
Term
| Which proteins form a cage-like structure over the vesicle and promote membrane curvature and bud formation? |
|
Definition
|
|
Term
| What forms a ring around the base of the vesicle (monomeric GTPase; pinch of vesicle)? |
|
Definition
|
|
Term
| In a coated bud formation, transmembrane cargo receptors select ___ proteins. |
|
Definition
|
|
Term
| Which two molecules are released after bud formation? |
|
Definition
coat protein
adaptin molecules |
|
|
Term
| What sets up the specificity of fusion of a vesicle to the second compartment? |
|
Definition
|
|
Term
| The 'molecular marker' proteins identify the transport vesicles according to what two characteristics? |
|
Definition
|
|
Term
| 'Molecular marker' proteins and their receptors are known as what? |
|
Definition
|
|
Term
| What are membrane bound proteins that mediate the fusion of transport vesicles with their organelle called? |
|
Definition
|
|
Term
| What are the two groups that SNARE proteins are grouped into? |
|
Definition
v-SNARE (vesicle)
t-SNARE (target) |
|
|
Term
| What are the two roles of SNARE proteins? |
|
Definition
provide specificity
catalyze membrane fusion reaction |
|
|
Term
| What organelle does not have T-SNAREs |
|
Definition
|
|
Term
| What is excluded when the SNARE complexes catalyze membrane fusion? |
|
Definition
|
|
Term
| The _____ leaflet of the lipid bilayer fuses first. |
|
Definition
|
|
Term
| The _____ leaflet of the lipid bilayer fuses last. |
|
Definition
|
|
Term
| How many phospholipid molecules are in one transport vesicle? |
|
Definition
|
|
Term
| How many different transmembrane proteins are in one transport vesicle? |
|
Definition
|
|
Term
| How many copies of the proton ATPase are in one transport vesicle? |
|
Definition
|
|
Term
| How many cholesterol molecules are in one transport vesicle? |
|
Definition
|
|
Term
| How are some bacteria able to cause tetanus and botulism? |
|
Definition
| They secrete proteolytic neurotoxins that target the degradation of various SNARE complexes in neurons: result in neurotransmitter release |
|
|
Term
| What SNARE is targeted by C. botulinum (Botulinum toxin B)? |
|
Definition
|
|
Term
| What SNARE is targeted by Clostridium tetani (tetanus toxin)? |
|
Definition
|
|
Term
| What SNARE is targeted by C. botulinum(Botulinum toxin C)? |
|
Definition
|
|
Term
| What SNARE is targeted by C. botulinum (Botulinum toxin A)? |
|
Definition
|
|
Term
| What are the two modifications that occur in the ER? |
|
Definition
Disulfide bond formation: between cysteine, protein folds to different pH
Glycosylation: covalent attachment of 14 oligosaccharide group, protects from degradation, guide to appropriate organelle |
|
|
Term
| When does glycosylation occur? |
|
Definition
| As soon as the polypeptide chain enters the ER lumen |
|
|
Term
| What transfers the 14 sugar group to an asparagine residue |
|
Definition
| Oligosaccharide protein transferase |
|
|
Term
| What is the most common type of glycosylation? |
|
Definition
|
|
Term
| After the 14 sugar group is linked to asparagine by the oligosaccharide protein transferase (glycosylation), what is the protein called? |
|
Definition
|
|
Term
| What is the only way a protein can leave the ER? |
|
Definition
| protein must be fully folded and assembled |
|
|
Term
| What monitors the folding of proteins in the ER lumen? |
|
Definition
|
|
Term
| What happens to proteins that are unable to fold in the proper time period? |
|
Definition
|
|
Term
| 12 Transmembrane protein at the plasma membrane that functions as a chlorine channel; only 25% is properly folded, so 75% is degraded; regulates water flow across cell |
|
Definition
|
|
Term
| What three things happen to a protein once it enters the ER? |
|
Definition
amino-terminal signal is removed
chaperone proteins fold the protein
modified by glycosylation and disulfide bond formation |
|
|
Term
| What are the flattened membrane sacs in the golgi called? |
|
Definition
|
|
Term
| How many cisternae are there per Golgi sac? |
|
Definition
|
|
Term
| Where is the Golgi located in the cell? |
|
Definition
| adjacent to the nucleus (cap); facing the direction of cell movement |
|
|
Term
| What are the five functional domains of the Golgi? |
|
Definition
cis Golgi network (CGN)
cis cisterna
medial cisterna
trans cisterna
trans Golgi Network (TGN) |
|
|
Term
| Which domains of the Golgi function in sorting? |
|
Definition
Trans Golgi Network (TGN)
Cis Golgi Network (CGN) |
|
|
Term
| Which direction do the cis, medial, and trans cisterna domains of the golgi move? |
|
Definition
|
|
Term
| Where does Oligosaccharide processing take place? |
|
Definition
|
|
Term
| Where does Oligosaccharide assembly take place? |
|
Definition
| only in the Golgi; sugars added to hydroxyl group of Ser/Thr residues |
|
|
Term
| What is the function of the constitutive secretory pathway? |
|
Definition
| Delivers lipids and proteins to the plasma membrane and continual secretion of soluble proteins |
|
|
Term
| The constitutive secretory pathway doesn't need a ________. |
|
Definition
|
|
Term
| All material leaving the TGN follows what secretory pathway? |
|
Definition
|
|
Term
| What are the two types of secretory pathways? |
|
Definition
Constitutive (unregulated)
Regulated (signaled) |
|
|
Term
| Where does the segregation of proteins destined for the apical versus the basolateral surface of a cell occur? |
|
Definition
|
|
Term
| What two things direct the differential targeting of the TGN? |
|
Definition
amino acid sequence within the C-terminus of the cargo protein
association of the protein with a particular lipid environment |
|
|
Term
| What are examples of regulated secretory products? |
|
Definition
hormones
neurotransmitters
digestive enzymes |
|
|
Term
| In the regulated exocytosis pathway, the proteins aggregate in what type of conditions? |
|
Definition
| high Ca2+ and acidic pH (TGN conditions) to be released in large amounts |
|
|
Term
| Cargo targeted for regulated secretion accumulate to high concentrations in modified secretory vesicles called _____. |
|
Definition
|
|
Term
| What are two signal examples for the regulated exocytosis pathway? |
|
Definition
hormone binding to extracellular receptor
electrical excitation/action potential |
|
|
Term
| What signals the release of insulin from pancreatic beta cells? |
|
Definition
| increased glucose levels in the blood |
|
|
Term
| How many acid hydrolases (active only at acidic pH) does the lysosome contain? |
|
Definition
|
|
Term
| The lysosome works via _____ and _____ transport. |
|
Definition
| active and co-translational |
|
|
Term
| What helps maintain the low pH in the lysosome? |
|
Definition
|
|
Term
| What signal transports proteins to the golgi from the ER? |
|
Definition
| addition of N-linked oligosaccharide |
|
|
Term
| What tags proteins in the Golgi to be destined to the lysosome? |
|
Definition
|
|
Term
| Once in the lysosome, what happens to the mannose 6-phosphate? |
|
Definition
| removed due to acidic conditions and receptor is recycled |
|
|
Term
| What is the process of taking material into the cell by invagination of the plasma membrane and its internalization into endocytic vesicles for delivery to the lysosome? |
|
Definition
|
|
Term
| What are the two main types of endocytosis? |
|
Definition
Pinocytosis: cellular drinking
Phagocytosis: cellular eating |
|
|
Term
| What type of endocytosis involves the uptake of fluid and small molecules? |
|
Definition
|
|
Term
| What type of endocytosis involves the uptake of large extracellular particles including microorganisms and cell debris? |
|
Definition
|
|
Term
| Protozoans use _____ as a form of eating. |
|
Definition
|
|
Term
| What do animal cells use phagocytosis for? |
|
Definition
| defense system against infection |
|
|
Term
| How does a bacterium undergo Phagocytosis? |
|
Definition
Bacterium coated with antibodies binds to receptors.
Binding triggers extension of sheet-like projections (pseudopods)
the bacterium is engulfed and fused with lysosome and digested. |
|
|
Term
| Macrophages ingest more than _____ nonfunctional red blood cells per day. |
|
Definition
|
|
Term
| What allows for the uptake of minor components of the extracellular fluid without substantial increase in the uptake of extracellular fluid? |
|
Definition
| Receptor Mediated Endocytosis |
|
|
Term
| What three types of material are taken up through receptor mediated endocytosis? |
|
Definition
Cholesterol
Vitamin B12
Iron |
|
|
Term
| Cholesterol is transported in the blood stream as ______. |
|
Definition
| low density lipoproteins (LDL) |
|
|
Term
| Describe the mechanism for LDL uptake. |
|
Definition
Cholesterol transported in bloodstream as LDL and binds to receptors on cells
Receptors are brought into cell via endocytosis and fuses with endosome
Acidic pH releases the LDL form receptor
LDL is trafficked into the lysosome, broken down, and cholesterol is released to cytosol |
|
|
Term
| When do the LDL receptors endocytose into the cell? |
|
Definition
| continually; not dependent of bound LDL |
|
|
Term
| Iron uptake is a ____ dependent process. |
|
Definition
|
|
Term
| What pH does transferrin bind to iron? |
|
Definition
|
|
Term
| How do mycobacteria and salmonella avoid destruction once inside a host? |
|
Definition
| Once engulfed, the bacteria prevent phagosome-lysosome fusion allowing the bacteria to live in a protected intracellular environment avoiding detection. |
|
|
Term
| How do listeria monocytogenes avoid destruction once engulfed by macrophages? |
|
Definition
| Once engulfed, listeria secrete a protein that destroys the phagosome membrane releasing the bacteria into the cytoplasm of the cell and avoiding lysosomes altogether. |
|
|
Term
| What is transferrin called when it binds to iron at a pH of 5.5, releases iron, but stays bound to receptor? |
|
Definition
|
|
Term
| The _______ acts as a sorting station for material brought into the cell by endocytosis. |
|
Definition
|
|
Term
| What are the three pathways that a receptor can follow once in the endosome? |
|
Definition
Recycled back to plasma membrane (LDL)
Transported to lysosome where they are degraded.
Delivered to a different domain of the plasma membrane. |
|
|
Term
| What is moving material from one domain to another called? |
|
Definition
|
|
Term
| What are the three pathways that acquire material for degradation by the lysosome? |
|
Definition
Phagocytosis-uptake of large molecules
Endocytosis-internalization of plasma membrane proteins
Autophagy-disposal of old intracellular organelles or microbes |
|
|
Term
| What is the disposal of old intracellular organelles or microbes? |
|
Definition
|
|
Term
| What happens to enzymes that should go to lysosome, but are not bound to mannose-6-phosphate? |
|
Definition
| go to plasma membrane from the TGN (default pathway) |
|
|
Term
| Where do enzymes function? |
|
Definition
| inside the cell; need acidic environment |
|
|
Term
| What is the genetic mutation that results in the loss of GIcNAc phosphotransferase activity causing all macromolecules incorporated in lysosomes to remain undegraded forming "inclusion bodies" within the cell. |
|
Definition
| I-Cell Disease (Inclusion-Cell Disease); lack of mannos-6-phosphate tag |
|
|
Term
| What is a network of protein filaments that extend throughout the cytoplasm? |
|
Definition
|
|
Term
| What are the three cytoskeletal elements? |
|
Definition
Microtubles
Actin
Intermediate filaments |
|
|
Term
| Which cytoskeletal element is responsible for organelle positioning, chromosome segregation, and intracellular traffic? |
|
Definition
|
|
Term
| Which cytoskeletal element is responsible for cell shape and whole cell movement? |
|
Definition
|
|
Term
| Which cytoskeletal element is responsible for mechanical strength? |
|
Definition
|
|
Term
| The nuclear envelope is supported by ____. |
|
Definition
| meshwork of intermediate filaments |
|
|
Term
| How do the three cytoskeletal elements differ? |
|
Definition
subunits
assembly
roles
organization |
|
|
Term
| Which are the toughest of the three cytoskeletal filaments? |
|
Definition
|
|
Term
| How do intermediate filaments connect to each other? |
|
Definition
| They do not directly connect, but are associated via desmosome at cell junctions. Do not cross membrane. |
|
|
Term
| Describe the structure of monomeric subunits. |
|
Definition
Globular NH2 and C-terminal domains
Elongated central alpha-helical region |
|
|
Term
| Describe the structure of dimeric complex. |
|
Definition
Coiled-coil formation via alpha-helical domain
parallel organization of monomers |
|
|
Term
| Describe the structure of tetrameric complex. |
|
Definition
staggered association of two dimers
Antiparallel organization of dimers
noncovalent interactions
nonpolar filament formed |
|
|
Term
| Describe the structure of filament formation. |
|
Definition
end-to-end association of tetramers
noncovalent interactions |
|
|
Term
| Intermediate filaments are composed of ____ filaments end-to-end tetramers that have a ___ diameter |
|
Definition
|
|
Term
| What type of cells are intermediate filaments abundant in? |
|
Definition
neuronal axons
muscle cells
epithelial cells |
|
|
Term
| What are the four types of intermediate filaments? |
|
Definition
keratins
vimentin and vimentin-related
neurofilaments
nuclear lamins |
|
|
Term
| Which is the most diverse intermediate filament type? |
|
Definition
|
|
Term
| Where are Keratin filaments found? |
|
Definition
| in the cells that line the gut, epidermal layer, and hair/feathers/claws |
|
|
Term
| Keratin filaments are formed by a mixture of _____ |
|
Definition
|
|
Term
| Which disorder is caused by a mutation in keratin 5 and 14 genes? |
|
Definition
| Epidermolysis Bullosa Simplex |
|
|
Term
| Epidermolysis Bullosa Simplex is what kind of disorder? |
|
Definition
|
|
Term
| In Epidermolysis Bullosa Simplex, there are more than ____ mutations identified in each gene. |
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Definition
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Term
| What are the symptoms of Epidermolysis Bullosa Simplex? |
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Definition
| fragile epidermis is easily damaged (skin blistering) |
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Term
| What helps to stabilize intermediate filaments? |
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Definition
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Term
| What is an example of an accessory protein-intermediate filament relationship? |
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Definition
| Plectin (accessory protein) cross-links vimentin (intermediate filament) |
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Term
| What is the nuclear intermediate filament? |
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Definition
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Term
| A defect in the nuclear lamina causes ____. |
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Definition
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Term
| The ____ of the nuclear lamins promote nuclear envelope breakdown during mitosis |
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Definition
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Term
| The nuclear lamin disassembles and reforms where? |
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Definition
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Term
| Disassembly and reassembly of the nuclear lamin is controlled by _____. |
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Definition
| phosphorylation; weakens bonds that hold tetramers together |
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Term
| What triggers the reassembly of the nuclear lamin? |
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Definition
| Dephosphorylation at the end of mitosis |
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Term
| What is the diameter of a microtubule? |
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Definition
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Term
| What are the minus ends of microtubules attached to? |
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Definition
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Term
| What do centrosomes form by undergoing duplication during mitosis? |
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Definition
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Term
| Microtubules extend toward what? |
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Definition
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Term
| What do microtubules form in dividing cell? |
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Definition
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Term
| Where can stable microtubules be found? |
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Definition
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Term
| What are the cellular functions of the microtubules? |
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Definition
transport of vesicles
anchoring membrane-enclosed organelles
machinery for chromosome segregation
formation of cilia and flagella |
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Term
| How are tubulin heterodimers held together? |
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Definition
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Term
| How many protofilaments associate to form a single microtubule? |
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Definition
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Term
| Which cytoskeletal filament is the straightest? |
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Definition
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Term
| Describe the ends of microtubules. |
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Definition
polar; no charge
alpha - (embedded in centrosome)
beta + (where addition occurs) |
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Term
| What is a long linear string of subunits joined end-to-end? |
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Definition
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Term
| What about the microtubule is controlled by the centrosome? |
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Definition
| number, location, and orientation |
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Term
| how many gamma-tubulin ring complexes does a centrosome contain? |
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Definition
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Term
| What is the nucleating site for tubulin polymerization? |
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Definition
| gamma-tubulin ring complexes |
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Term
| What do the gamma-tubulin ring complexes bind to? |
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Definition
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Term
| What is the concentration like of free tubulin in vivo? |
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Definition
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Term
| What is a short clusters of microtubules arranged at right angles to each other, but are not directly involved in microtubule polymerization? |
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Definition
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Term
| What is the growing and shrinking of microtubules referred to? |
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Definition
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Term
| Which microtubule subunit can hydrolyze GTP to GDP? |
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Definition
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Term
| What happens to the rate of hydrolysis once when assembled into a filament? |
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Definition
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Term
| What is polymerization controlled by? |
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Definition
| The concentration of free subunits |
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Term
| How can the depolymerizing microtubule be "rescued" |
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Definition
| increases the free tubulin concentration |
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Term
| What are drugs known as that target microtubule instability? |
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Definition
| antimitotic drugs (used for cancer) |
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Term
| What causes cells to be unable to form a proper mitotic spindle; causing the spindle to disassemble. |
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Definition
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Term
| Where does the drug Vinblastine come from? |
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Definition
| Madagascar periwinkle plant |
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Term
| Where does the drug Colchicine come from? |
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Definition
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Term
| What causes cells to be unable to depolymerize their microtubules and blocks chromosome segregation during mitosis? |
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Definition
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Term
| Which microtubule-specific drug binds and stabilizes the microtubule? |
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Definition
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Term
| Which microtubule-specific drugs binds subunits and prevents polymerization? |
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Definition
Colchicine, colcemid
vinblastine, vincristine |
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Term
| What is an example of "stabilized microtuble" generating cell polarity? |
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Definition
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Term
| What is the movement along microtubules dependent upon? |
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Definition
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Term
| What are two motor proteins associated with microtubules? |
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Definition
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Term
| What type of energy do the microtubule motor proteins use? |
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Definition
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Term
| In which direction do kinesins move in? |
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Definition
| move towards + end to deliver material outwards towards the cell periphery |
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Term
| In which direction do dyneins move in? |
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Definition
| move towards - end to deliver material inwards towards the centrosome |
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Term
| Cellular localization of organelles is dependent upon what? |
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Definition
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Term
| The ER stretches out to the periphery of the cell along the what? |
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Definition
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Term
| What localizes like a cap and surrounds the centrosome? |
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Definition
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Term
| What motor protein is responsible for the localization of the Golgi? |
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Definition
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Term
| What motor protein is responsible for the localization of the ER? |
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Definition
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Term
| Which motor protein is likely involved in transporting vesicles from the ER to the cis-Golgi network? |
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Definition
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