ESS 345 MIDTERM EXAM QUESTIONS AND
ANSWERS VERIFIED
What is the basic unit of contraction in Skeletal Muscle?
Sarcomere
Myofibril is ___________ of muscle fiber.
Component
At rest, ___________ is stored in the SR and release by action potential to bind to
___________ for muscle contraction.
Calcium; troponin
At rest, cross-bridge interaction between actin and myosin in skeletal muscle is
directly blocked by __________.
tropomyosin
What is it the tilting action of the head called when the myosin head pulls the thin
filament toward the center of the sarcomere?
Power Stroke
When a muscle fiber is stimulated so ________, that muscle fiber is not allowed to
relax between stimulations, resulting in a smooth and sustained contraction. This
phenomenon is called _____________.
Rapidly; tetanus
A motor unit refers to ___________.
A. a single motor neuron plus all of the muscle fibers it innervates
,B. a single muscle fiber plus all of the motor neurons that innervate it
C. all of the motor neuron supplying a single muscle
D. a pair of antagonist muscle.
A. a single motor neuron plus all of th emuscle fibers it innervates
If you wanted to pick up something heavier than your pencil, you would need to
have a stronger muscle contraction. In what way might you accomplish this?
A. stimulate more motor units
B. Decrease the frequency of stimulation to allow a more prolonged contraction
to occur.
C. Block acetylcholinesterase at the neuromuscular junction to allow
acetylcholine to function longer
D. None of the above is correct
A. Stimulate more motor units
If you want to hold a very heavy dumbbell to show your friends how strong you
are, you want to select the best joint angle ____________.
A. where muscle length is optimal
B. where energy supply is optimal
C. where leverage is maximal
D. A + B
E. A + C
E. A + C
- where muscle length is optimal
- where leverage is maximal
, What type of fibers are typically engaged during short, higher-intensity exercise
that involves some degree of endurance?
Type IIa
What type of fibers are not very easily stimulated by the nervous system,
meaning that they typically are not engaged until all other fiber types have been
stimulated first.
Type IIx
Which process is a transition from glycolysis to the Krebs Cycle?
A. Acetyl-CoA Formation
B. Conversion of PGASL to PGA
C. Regeneration of reduced NAD+
D. Oxidative Phosphorylation
A. Acetyl-CoA Formation
Under maximal effort, phosphocreatine (PCr) can provide enough energy to
synthesize ATP for ______________.
A. about 10 seconds
B. 30-45 seconds
C. 1-3 minutes
D. 3-6 minutes
A. about 10 seconds
Among 3 bioenergetic system, the greatest number of ATP molecules is
produced where?
The Electron Transport Chain
ANSWERS VERIFIED
What is the basic unit of contraction in Skeletal Muscle?
Sarcomere
Myofibril is ___________ of muscle fiber.
Component
At rest, ___________ is stored in the SR and release by action potential to bind to
___________ for muscle contraction.
Calcium; troponin
At rest, cross-bridge interaction between actin and myosin in skeletal muscle is
directly blocked by __________.
tropomyosin
What is it the tilting action of the head called when the myosin head pulls the thin
filament toward the center of the sarcomere?
Power Stroke
When a muscle fiber is stimulated so ________, that muscle fiber is not allowed to
relax between stimulations, resulting in a smooth and sustained contraction. This
phenomenon is called _____________.
Rapidly; tetanus
A motor unit refers to ___________.
A. a single motor neuron plus all of the muscle fibers it innervates
,B. a single muscle fiber plus all of the motor neurons that innervate it
C. all of the motor neuron supplying a single muscle
D. a pair of antagonist muscle.
A. a single motor neuron plus all of th emuscle fibers it innervates
If you wanted to pick up something heavier than your pencil, you would need to
have a stronger muscle contraction. In what way might you accomplish this?
A. stimulate more motor units
B. Decrease the frequency of stimulation to allow a more prolonged contraction
to occur.
C. Block acetylcholinesterase at the neuromuscular junction to allow
acetylcholine to function longer
D. None of the above is correct
A. Stimulate more motor units
If you want to hold a very heavy dumbbell to show your friends how strong you
are, you want to select the best joint angle ____________.
A. where muscle length is optimal
B. where energy supply is optimal
C. where leverage is maximal
D. A + B
E. A + C
E. A + C
- where muscle length is optimal
- where leverage is maximal
, What type of fibers are typically engaged during short, higher-intensity exercise
that involves some degree of endurance?
Type IIa
What type of fibers are not very easily stimulated by the nervous system,
meaning that they typically are not engaged until all other fiber types have been
stimulated first.
Type IIx
Which process is a transition from glycolysis to the Krebs Cycle?
A. Acetyl-CoA Formation
B. Conversion of PGASL to PGA
C. Regeneration of reduced NAD+
D. Oxidative Phosphorylation
A. Acetyl-CoA Formation
Under maximal effort, phosphocreatine (PCr) can provide enough energy to
synthesize ATP for ______________.
A. about 10 seconds
B. 30-45 seconds
C. 1-3 minutes
D. 3-6 minutes
A. about 10 seconds
Among 3 bioenergetic system, the greatest number of ATP molecules is
produced where?
The Electron Transport Chain
