Cross-bridge Cycling.

Question 1

During contraction the area of:

Answer 1

Overlap increases between thick & thick filaments increases.

Question 2

During contraction:

Answer 2

The A band stays the same size.

The I band and H zone stay the same size.

The sarcomere shortens.

Question 3

Cross-bridge cycle:

Answer 3

A series of repeating steps that produce filament sliding & muscle fiber contraction.

10nm slide per cycle.

Question 4

Cocking movement leads to the:

Answer 4

Cocked position of the cross bridge.

Question 5

ATP hydrolysis:

Answer 5

ATP is hydrolyzed into ATP + P.

ATP binds to the ATPase site.

P is released first; ATP is released after.

Question 6

Released energy from ATP hydrolysis is stored in:

Answer 6

The cross bridge.

Question 7

Stored energy causes:

Answer 7

The cross-bridge to move to the cocked position.

Question 8

Cross-bride cycle [1]:
Rigor:

Answer 8

The ATPase site is empty. [No energy]

The cross-bridge is in the uncocked position.

Cross-bridge has an affinity for actin.

Question 9

Cross-bridge cycle [2]:

Answer 9

ATP binds to the ATPase site.

Affinity for the thin filament is decreased.

The cross-bride detaches from the thin filament.

Question 10

Cross-bridge cycle [3]:

Answer 10

ATP hydrolysis occurs.

Energy is stored in the cross-bridge.

Cross-bride moves to the cocked position.

Affinity for actin increases.

• Crossbridge binds to the thin filaments.

Question 11

Cross-bridge cycle [4]:

Answer 11

Pi is released from the ATPase site.

The release of Pi causes a power stroke.

Crossbridge moves from cocked to uncocked position.

This causes filament sliding.