Cross Bridge Cycle

<p>Jan 13, 2015 06:27 PM</p>

<p>

outstanding and clear; &nbsp;ATP induced crossbridge cycle.</p>

<p>

contrac of skel muscle...</p>

<p>

cross bridge cycle...</p>

<p>

sarcomere &nbsp;(one cylinder)</p>

<p>

myosin heads in thick myofilaments

interact with actin in thin myofils.</p>

<p>

Calc binds to troponin and it changes shape.</p>

<p>

tropomyosin moves away and exposes binding sites.</p>

<p>

myosin head &nbsp;must be in cocked position &nbsp;(gets there via hydrolyssi fo ATP)</p>

<p>

step 1: &nbsp;X bridge formation.... &nbsp;&nbsp;activ &nbsp;head binds.</p>

<p>

step 2 &nbsp;power stroke... &nbsp;ADP is released &nbsp;</p>

<p>

step3 &nbsp;&nbsp;X bridg &nbsp;detachment &nbsp;when &nbsp;another ATP binds...</p>

<p>

step 4 &nbsp;reac tiv &nbsp;requires hydrolys of &nbsp;ATP to adp. &nbsp;=> cocked position.</p>

<p>

&nbsp;

ends when &nbsp;Calc goes back to &nbsp;sarcoplas reticulum.</p>

<p>

&nbsp;</p>

<p>

&nbsp;</p>