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26 Cards in this Set
- Front
- Back
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What is the function of cofilin?
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a family of actin-binding proteins which disassembles actin filaments by cutting (-) end
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What is the function of ezrin?
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a protein-tyrosine kinase substrate in microvilli which serves as an intermediate between the plasma membrane and the actin cytoskeleton. It plays a key role in cell surface structure adhesion, migration, and organization.
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What determines which head region is bound in myosin?
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the tail region determines which head region is bound
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What is the function of myosin class I? Where are is it located?
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-membranes
-endocytosis |
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What is the function of myosin class II? Where are is it located?
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-involved in contraction
-muscle & non-muscle cells |
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What is the function of myosin class V?
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-can bind to receptor
-used in transport |
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What is the function of myosin class VI?
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-moves along (-) end of actin
-transport towards the ECM -1 ATP for movement of myosin |
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What is the function of titin?
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-stabilize myosin/help keep myosin on the Z disk
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What controls the organization of actin in the cell?
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Rho family of small G proteins
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What is chemotaxis?
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cell senses soluble molecule then moves up the concentration gradient
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What is the function of nebulin?
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a thin filament "ruler" and regulates thin filament length during sarcomere assembly
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What is the function of the sarcoplasmic reticulum?
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the sarcoplasmic reticulum stores and pumps calcium ions. The sarcoplasmic reticulum contains large stores of calcium, which it sequesters and then releases when the cell is depolarized. This has the effect of triggering muscle contraction.
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What is the function of Arp 2/3? How is it activated?
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-mediates branching
-activated by binding to WASp |
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How is WASp activated?
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by binding to a monomeric G protein (in the Rho family)
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Where is fimbrin located?
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microvilli, filopodia, and focal adhesions
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Where is alpha actinin located?
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stress fibers, filopodia, muscle z lines
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Where is spectrin located?
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Cell cortex
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Where is filamin located? What is its function?
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-leading edge, stress fibers, filopodia
-cross-link actin filaments |
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Where is dystrophin located?
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linking membrane proteins to actin cortex in muscle
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What are the domains of myosin?
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Head, neck, and tail
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How does myosin use ATP to pull on an actin filament?
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1) binds ATP, head released from actin
2) Hydrolysis of ATP to ADP and Pi, myosin head rotates into "cocked" state 3) Myosin head binds actin filament 4) "Power stroke": release of P and elacstic energy straightens myosin; moves actin filament left 5) ADP released, ATP bound; head released from actin |
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How does myosin move along actin filaments?
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hand over hand
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What is the A band?
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myosin filaments in skeletal muscle sarcomeres
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What happens when striated muscle contracts?
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the (-) end of acting move toward each other with the addition of ATP and Ca2+
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Where are myosin I and myosin II localized during cytokinesis?
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myosin II- contractile ring/cleavage furrow
myosin I- pole |
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How does cytoplasmic steaming occur?
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by myosin moving along actin filaments
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