Bio 465 Exam 2 Questions And All
Correct Answers.
what is responsible for a sarcomere shortening during muscle contraction? - Answer actin
filaments slide past myosin filaments
what is true about H zones and I bands? - Answer H zones only contain thick filaments and I
bands only contain thin filaments
what occurs when muscle contraction results in sarcomere shortening? - Answer H band width
stays the same and I band narrows
in skeletal muscle cells, contraction is initiated when Ca2+ binds to _________? - Answer
troponin
what initiates the detachment of cross-bridge heads from the thin filament? - Answer ATP
binding to the myosin head
what results in the transfer of energy into the conformational state of cross-bridges? - Answer
ATP being hydrolyzed into ADP and Pi (phosphate)
what is most closely associated with the conformational change of the myosin head that moves
the thin filament? - Answer the dissociation of ADP and Pi from the cross bridge head
rigor mortis is the stiffness of skeletal muscles after death due to the loss of ability to
resynthesize ATP. What chemical formula represent the state of cross-bridges in rigor mortis? -
Answer A•M
what best represents the chemical state of resting muscle? - Answer A+M•ADP•Pi
most of the energy used by muscles during a 45-second Sprint is obtained from what source? -
Answer muscle glycogen
what happens to the proportion of energy derived from muscle glycogen as the duration of
, as the duration of exercise increases, what change occurs in the proportion of energy drive from
plasma free fatty acids - Answer there is an increase
what is the source of most of the plasma free fatty acids? - Answer hydrolysis of stored
adipose
ACh (acetylcholine) is released from the motor neurons and enters the _________ - Answer
synaptic cleft
acetylcholine causes an EPP (end-plate potential) by triggering the ________ - Answer
opening of Na+ channels
thin filaments - Answer composed primarily of intertwined actin myofilaments and extend
perpendicularly from each Z disk
z disc - Answer form the boundary of each sarcomere and separate sarcomeres from each
other
thick filament - Answer largely composed of myosin myofilaments and radiate out from the
central M line
M line - Answer center of sarcomere
Energizing the myosin head reaction - Answer H2O+ATP=ADP+Pi+H+
regulatory protein complex - Answer formed by tropomyosin and troponin
active binding sites on actin are exposed by _________ - Answer Ca2+ released from the SR
binding directly to troponin causing a conformational change in both regulatory proteins
tropomyosin and troponin
cross-bridge formation - Answer occurs as the energized myosin heads bind to the newly
exposed myosin binding sites on the actin
Correct Answers.
what is responsible for a sarcomere shortening during muscle contraction? - Answer actin
filaments slide past myosin filaments
what is true about H zones and I bands? - Answer H zones only contain thick filaments and I
bands only contain thin filaments
what occurs when muscle contraction results in sarcomere shortening? - Answer H band width
stays the same and I band narrows
in skeletal muscle cells, contraction is initiated when Ca2+ binds to _________? - Answer
troponin
what initiates the detachment of cross-bridge heads from the thin filament? - Answer ATP
binding to the myosin head
what results in the transfer of energy into the conformational state of cross-bridges? - Answer
ATP being hydrolyzed into ADP and Pi (phosphate)
what is most closely associated with the conformational change of the myosin head that moves
the thin filament? - Answer the dissociation of ADP and Pi from the cross bridge head
rigor mortis is the stiffness of skeletal muscles after death due to the loss of ability to
resynthesize ATP. What chemical formula represent the state of cross-bridges in rigor mortis? -
Answer A•M
what best represents the chemical state of resting muscle? - Answer A+M•ADP•Pi
most of the energy used by muscles during a 45-second Sprint is obtained from what source? -
Answer muscle glycogen
what happens to the proportion of energy derived from muscle glycogen as the duration of
, as the duration of exercise increases, what change occurs in the proportion of energy drive from
plasma free fatty acids - Answer there is an increase
what is the source of most of the plasma free fatty acids? - Answer hydrolysis of stored
adipose
ACh (acetylcholine) is released from the motor neurons and enters the _________ - Answer
synaptic cleft
acetylcholine causes an EPP (end-plate potential) by triggering the ________ - Answer
opening of Na+ channels
thin filaments - Answer composed primarily of intertwined actin myofilaments and extend
perpendicularly from each Z disk
z disc - Answer form the boundary of each sarcomere and separate sarcomeres from each
other
thick filament - Answer largely composed of myosin myofilaments and radiate out from the
central M line
M line - Answer center of sarcomere
Energizing the myosin head reaction - Answer H2O+ATP=ADP+Pi+H+
regulatory protein complex - Answer formed by tropomyosin and troponin
active binding sites on actin are exposed by _________ - Answer Ca2+ released from the SR
binding directly to troponin causing a conformational change in both regulatory proteins
tropomyosin and troponin
cross-bridge formation - Answer occurs as the energized myosin heads bind to the newly
exposed myosin binding sites on the actin
