BIO 465 Prep Exam 2 Questions With
Guaranteed Pass Solutions.
Which of the following is responsible for sarcomere shortening during muscle contraction? -
Answer Actin filaments slide past myosin filaments.
Which of the following statements about H zones and I bands is TRUE? - Answer The H zones
contain thick filaments but no thin filaments, while the I bands contain thin filaments but no
thick filaments.
When muscle contraction results in sarcomere shortening, which of the following occurs? -
Answer The A band remains the same width but the I band narrows.
In skeletal muscle cells, contraction is initiated when Ca2+ binds to which of the following? -
Answer Troponin
Which of the follwing initiates the detachment of cross-bridge heads from the thin filament? -
Answer ATP binding to the myosin head
Which of the following results in the transfer of energy into the conformational state of cross-
bridges? - Answer ATP is hydrolyzed into ADP and phosphate
Which of the following 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 loss of the ability resynthesize
ATP. Which of the following chemical formulae represent the state of cross bridges in rigor
mortis? - Answer A-M
Which of the following 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 which of the
following sources? - Answer Muscle glycogen
, After three hours of exercise what are the two main sources that provide energy for muscle
contraction? - Answer Blood glucose and plasma free fatty acids
As the duration of exercise increases, what change occurs in the proportion of energy derived
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
The region where the neuronal signal is transferred to the muscle is called _____________. -
Answer Neuromuscular Junction
Acetylcholine (ACh) is released from motor neurons and enters the _______________ - Answer
synpatic cleft
Acetylcholine causes an end-plate potential by triggering the __________________ - Answer
opening of Na+ channels
Thin filaments connect to and extend from either side of a/an __________________. These thin
filaments are composed largely of the myofilament _____________. - Answer Z disc; actin
Myosin heads directly use __________________ to transition to their confomation, which
enables them ready to bind to actin. - Answer ATP; energized
The binding of epinephrin to its receptor activates an intracellular - Answer G protein
The activated G protein stimulates ______________ to produce large amounts of cyclic AMP -
Answer adenylyl cyclase
Which of these occurs during a isometric contraction of a skeletal muscle? - Answer
Sarcomere length does not change significantly
Compared to type 1 (slow oxidative) skeletal muscle fibers, how are type 2X (fast-glycolytic)
skeletal muscle fibers different? - Answer Type 2X fibers fatigue more readily
Guaranteed Pass Solutions.
Which of the following is responsible for sarcomere shortening during muscle contraction? -
Answer Actin filaments slide past myosin filaments.
Which of the following statements about H zones and I bands is TRUE? - Answer The H zones
contain thick filaments but no thin filaments, while the I bands contain thin filaments but no
thick filaments.
When muscle contraction results in sarcomere shortening, which of the following occurs? -
Answer The A band remains the same width but the I band narrows.
In skeletal muscle cells, contraction is initiated when Ca2+ binds to which of the following? -
Answer Troponin
Which of the follwing initiates the detachment of cross-bridge heads from the thin filament? -
Answer ATP binding to the myosin head
Which of the following results in the transfer of energy into the conformational state of cross-
bridges? - Answer ATP is hydrolyzed into ADP and phosphate
Which of the following 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 loss of the ability resynthesize
ATP. Which of the following chemical formulae represent the state of cross bridges in rigor
mortis? - Answer A-M
Which of the following 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 which of the
following sources? - Answer Muscle glycogen
, After three hours of exercise what are the two main sources that provide energy for muscle
contraction? - Answer Blood glucose and plasma free fatty acids
As the duration of exercise increases, what change occurs in the proportion of energy derived
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
The region where the neuronal signal is transferred to the muscle is called _____________. -
Answer Neuromuscular Junction
Acetylcholine (ACh) is released from motor neurons and enters the _______________ - Answer
synpatic cleft
Acetylcholine causes an end-plate potential by triggering the __________________ - Answer
opening of Na+ channels
Thin filaments connect to and extend from either side of a/an __________________. These thin
filaments are composed largely of the myofilament _____________. - Answer Z disc; actin
Myosin heads directly use __________________ to transition to their confomation, which
enables them ready to bind to actin. - Answer ATP; energized
The binding of epinephrin to its receptor activates an intracellular - Answer G protein
The activated G protein stimulates ______________ to produce large amounts of cyclic AMP -
Answer adenylyl cyclase
Which of these occurs during a isometric contraction of a skeletal muscle? - Answer
Sarcomere length does not change significantly
Compared to type 1 (slow oxidative) skeletal muscle fibers, how are type 2X (fast-glycolytic)
skeletal muscle fibers different? - Answer Type 2X fibers fatigue more readily
