front 1 2) Which muscle cells have the greatest ability to regenerate? A) skeletal | back 1 no data |
front 2 9) Calcium ions bind to the ________ molecule in skeletal muscle cells. A) actin | back 2 no data |
front 3 10) Myoglobin ________. A) breaks down glycogen B) is a protein involved in the direct phosphorylation of ADP C) stores oxygen in muscle cells D) produces the end plate potential | back 3 no data |
front 4 11) An elaborate network of membranes in skeletal muscle cells that
functions in calcium storage A) sarcoplasmic reticulum | back 4 no data |
front 5 12) A sarcomere is ________. A) the nonfunctional unit of skeletal muscle B) the area between two Z discs C) the area between two intercalated discs D) the wavy lines on the cell seen in the microscope | back 5 no data |
front 6 13) Immediately following the arrival of the stimulus at a skeletal
muscle cell there is a short A) contraction | back 6 no data |
front 7 14) Creatine phosphate functions in the muscle cell by ________. A) forming a temporary chemical compound with myosin B) forming a chemical compound with actin C) inducing a conformational change in the myofilaments D) storing energy that will be transferred to ADP to resynthesize
ATP | back 7 no data |
front 8 18) Which of the following are composed of myosin? A) thick filaments | back 8 no data |
front 9 19) During muscle contraction, myosin cross bridges attach to which active sites? A) myosin filaments | back 9 no data |
front 10 20) Which of the following surrounds the individual muscle cell? A) perimysium | back 10 no data |
front 11 22) Rigor mortis occurs because ________. A) the cells are dead B) sodium ions leak out of the muscle C) no ATP is available to release attached actin and myosin molecules D) proteins are beginning to break down, thus preventing a flow of
calcium ions | back 11 no data |
front 12 25) The oxygen-binding protein found in muscle cells is ________. A) hemoglobin | back 12 no data |
front 13 26) The contractile units of skeletal muscles are ________. A) microtubules | back 13 no data |
front 14 28) One functional unit of a skeletal muscle is ________. A) a sarcomere | back 14 no data |
front 15 33) During vigorous excercise, there may be insufficient oxygen
available to completely break A) a strong base | back 15 no data |
front 16 34) When a muscle is unable to respond to stimuli temporarily, it is
in which of the following A) relaxation period | back 16 no data |
front 17 35) In an isotonic contraction, the muscle ________. A) changes in length and moves the ʺloadʺ B) does not change in length but increases tension C) never converts pyruvate to lactate D) rapidly resynthesizes creatine phosphate and ATP | back 17 no data |
front 18 36) The muscle cell membrane is called the ________. A) endomysium | back 18 no data |
front 19 38) The mechanism of contraction in smooth muscle is different from
skeletal muscle in that A) actin and myosin interact by the sliding filament mechanism B) the trigger for contraction is a rise in intracellular calcium C) the site of calcium regulation differs D) ATP energizes the sliding process | back 19 no data |
front 20 41) Which of the following is true about smooth muscle contraction? A) Certain smooth muscle cells can actually divide to increase their numbers. B) Smooth muscle, in contrast to skeletal muscle, cannot synthesize
or secrete any C) Smooth muscle cannot stretch as much as skeletal muscle. D) Smooth muscle has well-developed T tubules at the site of
invagination. | back 20 no data |
front 21 42) Smooth muscle is characterized by all of the following except ________. A) it appears to lack troponin B) there are more thick filaments than thin filaments C) there are no sarcomeres D) there are noncontractile intermediate filaments that attach to
dense bodies within the cell | back 21 no data |
front 22 46) An anaerobic metabolic pathway that results in the production of
two net ATPs per glucose A) the citric acid cycle | back 22 no data |
front 23 49) After nervous stimulation stops, ACh in the synaptic cleft is
prevented from continuing A) calcium ions returning to the terminal cisternae B) the tropomyosin blocking the myosin once full contraction is achieved C) acetylcholinesterase destroying the ACh D) the action potential stopped going down the overloaded T
tubules | back 23 no data |