University:
University of Iowa
Course:
BIOL 14120AAA | Diversity of Form and Function
Academic year:

2022
Views:

45

Pages:

2
Author:

Leilani Contreras

Clickers Lecture 22 1. An EPSP, a ______________ of the membrane of a _______________, would result from the opening of a ligand gated ___________ channel. A. depolarization; axon; potassium B. depolarization; dendrite; potassium C. depolarization; dendrite; sodium D. hyperpolarization; axon; potassium E. hyperpolarization; axon; sodium 2. The β-conotoxin produced by the cone snail inhibits the inactivation of voltage gated sodium channels. Therefore it would: A. prevent the passive response to stimulus by neurons. B. prevent the inflow of sodium ions during the rising phase of an action potential. C. allow the continued inflow of sodium ions during the falling phase of the action potential prolonging the depolarization D. prevent the outflow of potassium ions during the falling phase of the action potential. E. make it impossible to recover from hyperpolarization. 3. A. B. C. What is the role of sodium in skeletal muscle contraction? Sodium flows into a muscle cell to initiate and propagate the action potential. Sodium flows out of a muscle cell to initiate and propagate the action potential. Sodium binds to receptors on the sarcoplasmic reticulum triggering release of calcium. D. Sodium binds to myosin and acts as a cofactor for the myosin ATPase. E. None of the above; Sodium has no role in skeletal muscle contraction. 4. A. B. C. D. E. Tetanus is: the partial contraction and partial relaxation state of muscles at rest. a quick weak twitch of the muscle. solely due to the recruitment of multiple muscle fibers by many motor neurons. a strong sustained contraction of skeletal muscle. None of the above. 5. An analog of ATP, ADPX, will bind to myosin with high affinity just like ATP. This analog cannot be hydrolyzed into ADP and X. If skeletal muscle were treated with a large quantity of this analog what would likely occur? A. The muscle would be unable to contract because the myosin would be unable to bind the actin. B. The muscle would be unable to contract because the myosin is bound to the actin but can’t perform the power stroke. C. The muscle would function normally. D. The muscle would lock up similar to the state of rigor mortis. E. The rate of contraction of this muscle would increase greatly.