Sliding Filament Model

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vertciel
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Sliding Filament Model

Post by vertciel » Mon Sep 29, 2008 4:43 pm

Hello everyone:

In my 7th edition Campbell and Reece Biology textbook, a diagram depicts the sliding filament model as a process in which the myosin head cuases the thin filament (Actin) to move toward the centre of sarcomere (i.e. a one-way process).

However, I am wondering how the actin would revert to its normal position after contracting.

Thanks!

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mith
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Post by mith » Mon Sep 29, 2008 9:50 pm

the atp is removed after each contraction
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Accepting hardships as the pathway to peace;
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vertciel
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Post by vertciel » Mon Sep 29, 2008 11:46 pm

Thanks for your reply, mith.

However, how does the actin revert after the removal of the ATP?

Does it revert normally (like a released spring) or must myosin heads pull it back?

ivan
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Re: Sliding Filament Model

Post by ivan » Thu Oct 02, 2008 11:32 am

The resulting decrease in calcium concentration causes the thin filament to slide back past the thick filament and the muscle to relax.

hehe..that will be our lesson tomorrow. hope, it'll help. :|

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Post by Darby » Thu Oct 02, 2008 4:00 pm

To a large extent, a contracted skeletal muscle doesn't revert until it's pulled out by the antagonist, so you could say that the filaments are physically pulled back into place once they are no longer bound.

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