31 terms

Ch. 10 Muscular Tissue Quiz 2

Type of structural protein that stabilizes the position of myosin
Category of proteins that switches the contraction process on and off
action potentials
What causes the release of calcium from the SR into the muscle cell
Type of protein that links the thin filaments to the sarcolemma
Category of proteins that generates the force during contraction
The forcefulness of a muscle contraction depends on the ____ of the sarcomere
Type of protein that provides a site where a myosin head can attach
Actin/ Thin
During the sliding filament mechanism which filament is pulled toward the center
Which type of contractile protein converts ATP to energy of motion
Category of proteins that aligns the thick and thin filaments properly
Which ion is most important in starting the contraction of the muscle
ATP Hydrolysis/ Formation of cross Bridges/ Power Stroke/ Detachment of myosin from Actin
List the four steps of the contraction cycle (In order)
Z discs
seperate one sarcomere from the next
A band
middle part of sarcomere where thick and thin filaments overlap one another
I band
lighter part of a sarcomere, contains thin but no thick filaments
H zone
center of each A band which contains thick but not thin filaments
M line
supporting proteins that hold the thick filaments together in the H zone
muscle proteins
what are myofibrils built from
troponin, tropomyosin
two types of regulatory proteins
myosin, actin
two types of contractile proteins
titin, dystrophin
two types of structural proteins
sliding filament mechanism
myosin heads attach to and walk along thin filaments at both ends of a sarcomere
what happens to the sarcomere and muscle after the sliding filament mechanism?
contraction cycle
the onset of contraction begins with the SR releasing calcium ions into the muscle cell, where they bind to actin opening the myosin binding sites
ATP hydrolysis
step where hydrolosis of ATP reorients and energizes the myosin head
formation of cross-bridges
step where myosin head attaches to the myosin-binding site on actin
power stroke
step when the crossbridge rotates, sliding the filaments
detachment of myosin from actin
step when as the next ATP binds to the myosin head, the hyosin head detaches from actin
ATP, Ca++
the contraction cycle repeats as long as what two things are available?
Ca++ pumps
the muscle cell membrane contains what that return Ca++ back to the SR quickly?
what happens to the muscle as the Ca++ level in the cell drops?