Skeletal muscle fibers contain sarcomeres; smooth muscle fibers do not.
Which muscle fiber type is best suited for endurance activities, such as long-distance jogging?
A) fast glycolytic fibers
B) fast oxidative fibers
C) slow oxidative fibers
D) slow glycolytic fibers
Which pathway for regenerating ATP provides the majority of the energy used for muscle activity during 30 minutes of light to moderate exercise?
A) direct phosphorylation of ADP by creatine phosphate
B) anaerobic glycolysis
C) use of stored ATP
What is the role of tropomyosin in skeletal muscles?
A) Tropomyosin serves as a contraction inhibitor by blocking the actin binding sites on the myosin molecules.
B) Tropomyosin is the chemical that activates the myosin heads.
C) Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules.
D)Tropomyosin is the receptor for the motor neuron neurotransmitter.
Skeletal muscle cells use creatine phosphate instead of ATP to do work
dC) slow oxidative fibers
eD) aerobic respiration
5 Multiple Choice Questions
stretching of the muscle
B) smooth muscle
5 True/False Questions
Only ________ muscle cells are always multinucleated. → skeletal
Which muscle characteristic describes the ability of muscle to respond to a stimulus?
D) excitability → C) load placed on the muscle
The thin filaments (actin) contain a polypeptide subunit G actin that bears active sites for myosin attachment. → sarcomere
The first step toward generating a skeletal muscle contraction is ________.
A) binding of the myosin heads to actin
B) a rise in intracellular Ca2+ levels
C) binding of ATP to the myosin heads
D) stimulation of the muscle by a nerve ending → B) intracellular levels of Ca2+
In an isotonic contraction, the muscle ________.
A) rapidly resynthesizes creatine phosphate and ATP
B) changes in length and moves the "load"
C) never converts pyruvate to lactate
D) does not change in length but increases tension → C