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9 Cards in this Set
- Front
- Back
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What is subunit of microfilaments? |
Actin monomers |
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Structure of microfilaments? |
Double helix of actin monomers Smallest in diameter of cytoskeleton Thinnest most flexible. Also polar and dynamic |
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Polymerisation/depolymerisation of microfilaments? |
1.When ATP binds to actin = POLYMERISATION. 2.ATP hydrolysed to ADP = DEPOLYMERISATION. |
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Where are microfilaments found? |
Throughout cytoplasm & highly concentrated in cell cortex. |
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Why are mocrofilaments highly concentrated in cell cortex? |
To help reinforce cell membrane and give mechanical strength in terms of structure and organisation |
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Do microfilaments involve cell crawling? |
Depends on actin microfilaments. Not all cells are stationary some move or crawl. Increased actin polymerisation allows cell to move in certain directions. |
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Actin |
Dynamic - control behaviour of actin filaments. Microfilaments found in Cross linked bundles, gel-like bundles & contractile bundle through cross-link with different proteins. E.g microvillus |
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Microfilaments & mitosis |
In mitosis, separation of cytoplasm for 2 daughter cells occurs where each has their own plasma membrane. The ring of actin filaments action/contraction of these myosin allow separation. |
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Myosin |
Motor protein, which allows sliding of microfilaments = contraction but requires ATP. |
