Term
| What is the diameter of microtubules? |
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Definition
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Term
| Give me some details on the structure of microtubules |
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Definition
| It is made from 13 circularly arrayed globular dimeric proteins. Part alpha part beta. Alpha faces to the (-) end and beta faces towards the (+) end. |
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Term
| Longitudinal contacts between dimers (alpha and beta tubulin) link them into a linear structure called... |
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Definition
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Term
| Microtubules grow from the _____a_____ within the ____b______ that serves as nucleation sites for each microtubule. |
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Definition
a- gamma-tubulin rings
b- MTOC |
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Term
| What is needed for polymerization of microtubules? |
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Definition
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Term
| Which proteins regulate microtubule assembly and anchor the microtubules to certain organelles. Also responsible for the existence of stable populations of non-depolymerizing microtubules, found in flagella and cilia. |
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Definition
| MAPs (microtubule-associated proteins) |
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Term
| What is this process called...microtubules constantly grow to cell periphery then shrink in direction of MTOC. |
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Definition
| Constant Remodeling Process or Dynamic Instability |
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Term
| What are 5 uses of microtubules? (IMACM) |
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Definition
1) intracellular vesicle transport
2) movement of cilia and flagella
3) attachment of chromosomes to the mitotic spindle and their movement in meiosis and mitosis.
4) Cell elongation and movement
5) Maintenance of cell shape, esp. its asymmetry |
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Term
| Move along microtubules to the minus end (capable of moving organelles from cell periphery toward the MTOC) |
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Definition
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Term
| Move along the microtubules toward the plus end; capable of moving organelles from the cell center to the periphery |
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Definition
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Term
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Definition
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Term
| free actin molecules in the cytoplasm |
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Definition
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Term
| polymerized actin in a filament |
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Definition
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Term
| fast growing end of actin |
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Definition
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Term
| slow growing end of actin |
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Definition
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Term
| Polymerization of actin requires |
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Definition
| K+, Mg2+, and ATP along with G-actin and ABPs |
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Term
| What proteins can prevent or enhance polymerization of actin? |
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Definition
| actin-binding proteins (ABPs) |
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Term
| proteins cross-link actin filaments into parallel arrays, creating actin filament bundles |
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Definition
| actin-bundling proteins (ex: fascin and fimbrin found in microvilli) |
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Term
| protein cuts actin filaments into short fragments |
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Definition
| Actin-filament-severing proteins (gelsolin) |
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Term
| blocks further addition of actin molecules by binding to free end of an actin filament |
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Definition
| Actin-capping proteins (tropomudulin- found in cardiac and skeletal muscles) |
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Term
| protein responsible for cross-linking actin filaments with each other |
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Definition
| Actin-cross linking proteins (spectrin, adduction, protein 4.1 and protein 4.9) |
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Term
| This protein hydrolyzes ATP to provide the energy for movement along the actin filament from the minus end to the plus end (belongs to the myosin family) |
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Definition
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Term
| What is often grouped in bundles close to the plasma membrane |
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Definition
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Term
| What are four functions of actin filaments? |
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Definition
1) anchoring and movement of membrane proteins (in focal adhesion, zonula adherens, and tight junctions)
2) core of microvilli and terminal web
3) locomotion of cells; lamellipodia
4) cell processes; filopodia |
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Term
| leading edge of a crawling cell; movement controlled by actin filaments |
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Definition
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Term
| small protrusion of cell containing 10 to 20 actin filaments organized in the same direction |
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Definition
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Term
| Cross-links involving which amino acid contribute most to the characteristic high tensile strength of collagen fibers? |
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Definition
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