The mechanism of muscle contraction is best explained by the sliding filament model. According to this model, thin ___i___ filaments slide over thick ___ii___ filaments. The statement given above is completed by information in row   Row i ii A. myosin actin B. myosin myosin C. actin actin D. actin myosin

Which of the following is a microscopic feature of a skeletal muscle fiber? a. It contains multiple nuclei that are centrally located b. it contains myoglobin for oxygen storage c. it contains glycosomes for glycogen storage d. a and b e. b and c

An ion that is essential for muscle contraction is Ca2+.  Which of the following statements about the calcium ion and muscle contractions is TRUE? Select one: a. Muscle contractions can occur whether Ca2+ concentrations are high or low.  b. Ca2+ binds to the tropin-tropomyosin protein complex shifting it out of the way and allows the myosin to bind to the actin so contraction can occur. c. When Ca2+ concentrations are high, tropomyosin inhibits myosin binding and the muscle is relaxed. d. Ca2+ ions are stored in the sacroplasmic reticulum during the muscle contractions. I do not know which one is

The structure (a specialized synapse) that allows neurons to control our skeletal muscle fibers is called the: 19. A. sarcolemma extracellular inard B. neuromuscular junction C. sarcoplasmic reticulum D. cross-bridge axiom arcople acell

the troponin/tropomyosin complex will inhibit the crossbridges of myosin from with actin. this is true during: A. Muscle relaxation B. Muscle contraction C. Nerve stimulation D. Both a & b

Crossbridges that form during muscle contraction are a bond between:   A. Myoglobin and Troponin B. Hemoglobin and Glycogen C. Actin and Myosin D. Toponin and Tropomyosin

Describe the following regions/structures of a sarcomere. (Fig 12.5)    A band - striated patterns of light and dark muscle fibers; scatters light unevenly; uses the entire length of thick filaments; the center of the band uses only thick filaments H zone  I band  M line  Z disc

An ion that is essential for muscle contraction is Ca2+.  Which of the following statements about the calcium ion and muscle contractions is TRUE? Select one: a. Muscle contractions can occur whether Ca2+ concentrations are high or low.  b. Ca2+ binds to the tropin-tropomyosin protein complex shifting it out of the way and allows the myosin to bind to the actin so contraction can occur. c. When Ca2+ concentrations are high, tropomyosin inhibits myosin binding and the muscle is relaxed. d. Ca2+ ions are stored in the sacroplasmic reticulum during the muscle contractions. i do not knwo which one is the answer

When a muscle fiber is stretched from 60% of its optimal length to Lo, what change or changes are happening on the cellular level (MULTIPLE SELECT)? A. Increased calcium release from the SR B. Increased firing of action potentials from the alpha motor neuron C. Increased rate of myosin ATPase activity D. Increased number of actin-myosin bridges E. Increased stretch on titin, producing more passive force

You know from experience that skeletal muscle tires quite quickly, especially if there is not enough oxygen. Interestingly, shellfish such as clams can maintain a month-long contraction in the muscle that keeps the shell closed. No oxygen gets in this situation. These muscles have a different version of myosin called paramyosin. Knowing what you know about the cellular mechanism of muscle contraction, propose a hypothesis to explain how paramyosin might work.