30. Calcium released from the sarcoplasmic reticulum is important because: A. It
ID: 163753 • Letter: 3
Question
30. Calcium released from the sarcoplasmic reticulum is important because: A. It binds with troponin which "charges" the so acti can bind. B. It binds with myosin blocking its coupling with actin and, therefore, inh muscle contraction. C. Both actin and myosin bind to calcium which acts as a cross-bridge all for muscle contraction. D. Calcium is used to create energy for muscle contraction, therefore spar ATP. 31. The contractile unit of muscle is called (a): A. Sarcoplasm. C. Nucleus. B. Myofibril. D. Sacromere. 32. Two ways in which muscles can be volitionally controlled so that force of s of contraction is matched to the task at hand are: A. Additional stimulation and accommodating resistance. B. Wave form differentiation and summary promulgation. C. Motor unit concentration and temporal resistance. 33. Which muscle fibers have the greatest aerobic capacity: C. Type IIB. A. Type IC. D. Type IIC. B. Type IIA. 34. Which of the following is correct? A. Type I fibers are preferentially recruited for sprinting. B. Type I fibers, because of their greater PC content, are used for pos C. Type II fibers are found in greater percentages in endurance athlet non-endurance athletes. D. Type I fibers have a relatively high aerobic capacity and fatique s 35. Type I fibers are: A. Always recruited regardless of exercise intensity. B. Only recruited during low intensity exercise. C. Only recruited during high intensity exercise. D. Recruited during both high and low intensity exercise but are not out maximal efforts.Explanation / Answer
Answer:
30). A. It binds with troponin which “charges” the cross-bridge complex so actin-myosin can bind.
Explanation:
Action potentials are electrical signals that tell muscle tissue to contract. As an action potential reaches a muscle cell, it triggers calcium to release from the sarcoplasmic reticulum of the cells. The calcium ions then flow into the cytoplasm and bind to the troponin and tropomyosin molecules in the actin filaments of the muscle cells. The binding of calcium allows the troponin to change shape and expose the actin-myosin binding site. Myosin then connects to actin, and the formed complex forms a cross bridge that opens and closes and allows the muscle cells to contract. After the contraction and action potential is over, the calcium channels close, and calcium is removed from the muscle cells.
31). D. Sarcomere
The basic structural and functional unit of a muscle cell is the sarcomere, which consists of thin filaments of the protein actin and thicker filaments of the protein myosin.
32). ---
33). A). Type IC
Type 1 muscle fibres have a higher count of mitochondria which means it can process energy quicker, it receives a good blood supply since it has a high amount of capillaries, which means it has a good supply of oxygen, which helps to maintain the use of the aerobic energy system for longer, making type 1 fibres more effect for endurance events
34). D). Type I fibers have relatively high aerobic capacity and fatigue resistance
35). B). Only recruited during low intensity exercise
Type I fibers are used in lower-intensity exercises such as very light resistance work aimed at muscular endurance and long-duration aerobic activities such as 5K and 10K runs.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.