Section X: Special Topics (B)
A patient anesthetized using a halothane compound exhibits a marked rise in body temperature, a behavior indicative of malignant hyperthermia (HT). Select the one of the following statements that is NOT CORRECT:
A. MH can arise from mutations that alter the amino acid sequence of the Na+-K+-ATPase.
B. MH can arise from mutations that alter the amino acid sequence of the ryanodine-sensitive Ca2+ release channel.
C. The muscle rigidity that occurs during MH is triggered by the presence of high concentrations of Ca2+ in the cytoplasm.
D. MH can arise from mutations that alter the amino acid sequence of the voltage-gated, slow K type Ca2+ channel.
E. MH can be treated by intravenous administration of dantrolene, which inhibits release of Ca2+ from the sarcoplasmic reticulum into the cytosol.
Select the one of the following statements that is NOT CORRECT:
A. F-actin is formed by the polymerization of G-actin.
B. Myosin is the major component of the thick filaments found in striated muscle.
C. Thin filaments are connected together by α-actinin.
D. The troponin system regulates the contraction of smooth muscle.
E. Ca2+ serves as a second messenger for regulating contraction in smooth, cardiac, and skeletal muscle.
Select the one of the following that is NOT a feature of the contractile cycle in striated muscle:
A. Binding of Ca2+ to troponin C uncovers the myosin binding sites on actin.
B. The power stroke is initiated by the release of Pi from the actin-myosin-ADP-Pi complex.
C. Release of ADP from the actin-myosin-ADP complex is accompanied by a large change in the conformation of myosin’s head domain (relative to its tail domain).
D. The binding of ATP by myosin increases its affinity for actin.
E. Rigor mortis results for the inability of actin to release from the actin myosin complex when cells are deficient in ATP.
Select the one of the following that does NOT serve as a major energy reserve for replenishing ATP in muscle tissue: