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96 Cards in this Set
- Front
- Back
Name the main components of the cytoskeleton
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microfilaments
intermediate filaments microtubules |
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______ are composed of actin and have a diameter of 6 to 7 nm
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microfilaments
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these filaments are made up of spectrin, vimentin, desmin, and cytokeratin
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intermediate filaments
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what are the largest of the cytoskeleton structures and made up of protein tubulin
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microtubles
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What are the main functions of the cytoskeleton
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overall structural support
contraction motility transport system cell division |
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this organelle has a transport system along which cytoplasmic vesicles move
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cytoskeleton
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the chromosomes must attach to the ______ in order to be correctly segregated to daughter cells
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cytoskeleton
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the _____ that forms the core of microfilaments is one of the most abundant, widely distributed, and highly conserved of all cytoskeletal elements
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actin
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what is G actin
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globular form that readily polymerizes into filamentous form
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what is F actin
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filamentous form of actin in a microfilament
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what is responsible for the sol get conversion of the cytoplasm
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microfilaments
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how would you describe sol
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relatively fluid consistency associated with abndance of G actin monomers
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does gel have more G actin or more F actin
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more F-- the filamentous form of actin in microfilaments
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relate microfilaments to microvilli
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actin makes up microfilaments which give the semi regid form to microvilli and similar structures
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in cells under tension, long actin filament are bundled into _____ _____
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coarse fibers. Important point here is that microfilametns are important in structural reinforcement of the cell by stress fibers
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what are the main functions of intermediate filaments
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structural support and resistance to mechanical stress
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spectrin, vimentin, desmin, and keratin make up what
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intermediate filaments
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____ is the cnetral component of a complex of proteins forming a meshwork close to the cytoplasmic face of the RBC plasma membrane and other slightly modified cell types
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spectrin
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T or F. Spectrin is a heterodimer.
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true composed of 220kD monomers that can also bind head to head and form tetramers
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spectrin is attached to the plasma membrane via an adaptor proteins called ______
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ankyrin
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ankyrin links ____ to an integral membrane protein called 4.1
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spectrin
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_____ is important in that it maintains the shape of the RBC while permitting it to squeeze through small capillaries
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spectrin
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what localizes both ryanodine and IP3 receptor in cardiomyocyte membranes
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spectrin
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______ are typicla constituents of epithelial cell intermediate filaments that are bundles that span the cell made up of 40kD to 60Kd
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keratins or cytokeratins
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microtubules are long cylinders of protien that typically radiate from aposition near the _____ outwards to the cortical actin at the plasma membrane
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nucleus
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what do microtubules do
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important for cell movement and morphology and also serve as the conduits along which vesicles travel through the cytoplasm
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T or F microtutubles are continuously being assembled and disassembled
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true
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does the minus or plus end of a microtubule point toward the nucleus
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minus
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why is the orientation minus toward nucleus and plus to PM of a microtubule important?
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essential for directional transport of vesicles and moelcules along tubules as well as for diretional growth of parts of particular cells such as neuronal axons
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what is the major microtubule organizing center for most cells?
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centrosome
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each centrosome has a pair of _____ inside
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centrioles
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each centriole consists of how many microtubule triplets
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9
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when do centrioles replicate
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prior to mitosis because they make up part of the mitotic spindle that chromosomes attach to during mitosis
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____ plays a major role in promoting and stabilizing microtubule assembly tomiantain the normal morphology of the neurons
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tau
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give a well known example of a tauopathy
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alzheimers
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centrioles can migrate toward the PM where they nucleate the formation of outgrowths termed ____ and ____
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cilia
flagella |
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what do you rename centrioles as in the formation of cilia or flagella
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basal bodies
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what is the 9+2 configuration
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9 pairs on microtubules around perimeter of 2 centrioles to make up a typical cilia
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give two examples of a MAPS proein
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microtubule associated proteins
kinesin dynein |
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the ______ driven sliding of microtubules against each other in cilia bring about their beating motion
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dynein
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list the biomembranes in a cell
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PM
nuclear envelope ER golgi vesicles membranes of mitochondria |
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what are the five functions of biomembranes
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barriers
facilitating diffusion establishing and maintaining ionic gradients acting as reactive surfaces transmitting signals |
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what kinds of molecules can travel passively through the biomembrane
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steroids and fat soluble vitamins (hydrophobic only)
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what kinds of molecules can diffuse through a biomembrane
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amino acis and glucose which are going down their conc gradient into the cell
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t or f. the display of membrane proteins is important in intracellular reactions, interactions between cells,a nd interactions between cells and their extracellular enviornment
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true
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t or f. biomembranes are frequently folded or form structures such as microvilli to increase their surface area
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true
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t or f cristae of the mitochondria is an example how biomembranes act as reactive surfaces
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true
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what does ampipathic mean
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have both hydrophilic and phobic domains
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many of the membrane proteins are _____ that have oligosacs bound to the peptide chain
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glycoproteins
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t or f. peripheral proteins are covalently linked to the internal or external face of the membrane
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FALSE non covalently
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the __ face is the inner surface of the outer lipid layer. The _ face is the outer surface of the inner lipid layer
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E P
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Does the E or P face have a higher density of proteins protruding
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P
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t or f. lipis and proteins are the same in the two halves of the bilayer
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FALSE
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This 10nm thick layer is found on the external surface of all PM and serves a variety of functions including mediating cell adhesion cell migration and nutrient absorption
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glycocalx
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what does the glycocalyx do?
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mediates cell adhesion
cell migration and nutrient absorption |
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what is an example of a cell that would want a large glycocalyx for function
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small intestine to attract food from the lumen into the cell
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why are biomembrane fluidity and flexibility important?
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for cell growth
division migration function |
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membrane fluidity is regulated in part by the _____ composition of the bilayer
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lipid.
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Many hydrophilic substances cross the membrane quite freely. But the PM is only slightly soluble to water? Why is this so?
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membrane proteins!
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is the surface of the membrane usually positively or negatively charged
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neg
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in some cells, glycolipids containing _____ _____ or amino sugars amke an important contribution to the net charge of the membrane
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sialic acid
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what are the three major categories of membrane proteins
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integral membrane proteins
lipid linked membrane proteins peripheral membrane proteins |
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see page 38! middle to continue
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go for it!
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what is it called when the integral protein domain only touches on one side of the bilayer
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monotopic
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the aminotermini of transmembrane proteins are usually hydrophilic and found on the _________ surfaces of the cell membranes and are often glycosylated
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extracellular
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the _____ termini of transmembrane proteins usally project as cytoplasmic tails
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carboxy
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extracellular lipid linked proteins are anchored to the exterior leaflet of the cell membrane by _____ group
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GPI
glycosyl phsphatidylinositol group |
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what are six types of integral proteins
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adhesion/linking
channel forming pumps enzymes receptors transducers |
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what do adhesion and linking proteins do
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bind the cell to other cells and sometimes have specialized junctions that allow the cells to communicate
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what type of integral protein forms aqueous channels through the membrane for diffusion of substances
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channel proteins
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gating proteins and transmembrane voltage or vote gated channels are what type of integral proteins
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channel
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what are three types of pumps
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uniports
symports antiports |
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T or F. pumps always require energy
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true
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t or f. enzymes can be considered integral proteins
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TRUE!
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what do transducers do
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proteins couple transmembrane receptors to cytoplasmic proteins such as enzymes. When a receptor bind a ligand, it initiates a cascade of enzymatic reaction in the cytoplasm through its transducers
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name the two major types of transport for water soluble molecules
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passive
active |
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is the inside of the cell usually positive or negative?
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neg
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passive and active transport are carred out by two major classes of membrane proteins. Name them
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carrier
channel proteins |
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Can carrier proteins be either active or passive?
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yes
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what kind of proteins form a narrow hydrophilic pore that allows the passive transport of small molecules
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channel proteins
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t or f. ALL channel proteins are passive transport and never active.
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TRUE
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____ channels are concerned with the transport of inorganic ions down their electrochemical gradients between the cell's interior and exterior
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ion channels
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regulation of the passage of molecules in ion channels occurs via ____ which open in repsonse to specific stimuli such as change in voltage, mechanical stress, or the binding of a ligand
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gates
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def. a transmembrane protein that allows cells ot bind one another or a substratum
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adhesion protein
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.2 to 1 micron lengths of microtubules triples arranged in 9+0 configuration that nucleate microtubules
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centriole (basal body)
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cell membrane evagination contianing a 9+2 core of microtubules
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cilium
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name the ATP dependent motor proteins of microtubules
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kinesin and dynein
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a region without a biomembrane that contains a functional group of proteins is called a
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functional domain
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def. an extracellular sugars attached to transmembrane proteins and lipids
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glycocalyx
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these 10nm cytoskeletal filaments are composed of cytodertains
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intermediate filaments
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def. 7nm cytoskeletal filaments composed of actin and associated proteins
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microtubules
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def. cell membrane evaginations containing a core of actin
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microvillus
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def. a bundle of actin filaments that provides support to the cell
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stress fiber
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proteins that couple transmembrane proteins usually receptors to cytoplasmic effector molecules such as enzymes
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transducer
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def. a lipid bilayer that has a trilaminar appearane in electron micrographs
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unit membrane
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t or f. lipid linked proteins are covalently linked to membrane
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true
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