Function of Ca+2 (Exam 2) Flashcards Preview

Spring of 2012 > Function of Ca+2 (Exam 2) > Flashcards

Flashcards in Function of Ca+2 (Exam 2) Deck (9)
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0
Q

A conformational change occurs in the actin

A

The troponin and tropomyosin shift and expose the binding site for myosin

1
Q

The AP travels across the sarcolemma and runs down the T Tubule

A

Causing Ca+2 to be released from the lateral sacs

The Ca+2 then binds to the TnC of troponin

2
Q

Myosin heads are now able to alternately bind and detach from actin

A

The hinge region of the myosin pulls the actin filaments toward the center of the sarcomere

3
Q

Siding filament theory

A
Actin slides toward the center of the sarcomere
Distance between the Z-disc is reduced
The I bands shorten
The H zone disappears
A bands move closer together
4
Q

The release of energy from the splitting of ATP (at the myosin ATPase binding site)

A

Powers the sliding filament theory

5
Q

The shortening of the sarcomere via actin and myosin attachment/detachment will continue

A

As long as Ca+2 is in the sarcomere allowing myosins binding site to be exposed

6
Q

For relaxation to take place

A

Ca+2 must be removed form the sarcomere

7
Q

Located on the surface of the SR

A

Is a Ca+2 ATPase pump

8
Q

Ca+2 ATPase pump

A

Using energy gained from splitting ATP it pumps Ca+2 out of the sarcomere and back into the lateral sacs

Troponin and tropomyosin recover myosins binding site
Actin and myosin are no longer attached and relaxation occurs (sarcomere lengthens back out)

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