What is the role of tropomyosin in a sarcomere?
A. It is the main protein component of thin myofilaments.
B. It is the main protein component in thick myofilaments.
C. It blocks the active sites on actin filaments in relaxed muscle fibers.
D. It binds to calcium to initiate muscle contraction.
E. It is the main component of elastic filaments.
Answer: C
You might also like to view...
Which of the following is FALSE regarding single-unit smooth muscle cells?
A. They have many gap junctions between cells. B. They may have pacemaker activity. C. They have an individual neuron innervating each individual smooth-muscle cell. D. They exhibit tone. E. They may respond to stretch by contracting.
________ is in high concentration in the pulmonary capillary blood.
A. Mucus B. Nitrogen C. Oxygen D. Carbon dioxide
Which of the following is true regarding bursitis?
A. overuse injury B. frictional irritation in one or more bursae C. inflammation D. both A and B E. all of the above
The process whereby nutrients are broken down during enzyme mediated reactions is ___.
a) elimination b) absorption c) mechanical digestion d) ingestion e) chemical digestion