BIOLOGY
12th Edition
ISBN: 9781260169614
Author: Raven
Publisher: RENT MCG
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 45, Problem 2A
You have identified a calcium storage disease in rats. How would this inability to store Ca2+ affect muscle contraction?
a. Ca2+ would be unable to bind to tropomyosin, which enables troponin to move and reveal binding sites for cross-bridges.
b. Ca2+ would be unable to bind to troponin, which enables tropomyosin to move and reveal binding sites for cross-bridges.
c. Ca2+ would be unable to bind to tropomyosin, which enables troponin to release ATP.
d. Ca2+ would be unable to bind to troponin, which enables tropomyosin to release ATP.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
What event causes a troponin-tropomyosin complex to regain its original shape in muscle relaxation? a. stimulation of ACh receptors b. diffusion of Na+ back into transverse tubules c. return of Ca2+ into the sarcoplasmic reticulum d. breaking of the bond with tropomyosin
In muscle cells, magnesium ions compete with calcium ions for binding sites on troponin molecules. If a person has too high a concentration of magnesium ions in the blood, magnesium ions can prevent calcium ions from binding troponin.
A) What effect would this have on muscle contraction (strengthen, weaken, or no effect)?
B) Use your knowledge of how muscle fibers contract to explain your answer in part A.
Myosin binds to actin, then bends. What is ATP needed for next?
A. to pump the Ca++ “keys” back into the sarcoplasmic reticulum
B. to replace the strap and cover the binding sites
C. to give feedback to the neuron that contraction occurred
D. to un-bind myosin from actin and re-set for another powerstroke.
Chapter 45 Solutions
BIOLOGY
Ch. 45.1 - Compare hydrostatic skeletons, exoskeletons, and...Ch. 45.1 - Explain how animals with hydrostatic skeletons...Ch. 45.2 - Prob. 1LOCh. 45.2 - Prob. 2LOCh. 45.2 - Prob. 3LOCh. 45.3 - Prob. 1LOCh. 45.4 - Prob. 1LOCh. 45.4 - Prob. 2LOCh. 45.4 - Prob. 3LOCh. 45.5 - Prob. 1LO
Ch. 45.5 - Describe how friction and gravity affect...Ch. 45.5 - Prob. 3LOCh. 45 - Prob. 1IQCh. 45 - Exoskeletons and endoskeletons differ in that a....Ch. 45 - Worms use a hydrostatic skeleton to generate...Ch. 45 - Bone develops by one of two mechanisms depending...Ch. 45 - Which of the following statements best describes...Ch. 45 - Motor neurons stimulate muscle contraction via the...Ch. 45 - Prob. 6UCh. 45 - If you wanted to study the use of ATP during a...Ch. 45 - Place the following events in the correct order....Ch. 45 - You take X-rays of two individuals. Ray has been a...Ch. 45 - You have identified a calcium storage disease in...Ch. 45 - How do the muscles move your hand through space?...Ch. 45 - How can osteocytes remain alive within bone? a....Ch. 45 - Swimming underwater using forelimbs for propulsion...Ch. 45 - If a drug inhibits the release of ACh, what will...Ch. 45 - Prob. 1SCh. 45 - Prob. 2SCh. 45 - The nerve gas methylphosphonofluoridic acid...Ch. 45 - If natural selection favors the evolution of wings...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- With regard to muscle contraction, which of the following is an INCORRECT statement with regard to the interactions of filaments that occur in the sarcomere? A. When muscles are relaxed tropomyosin blocks binding sites on actin subunits, which keeps cross-bridges from forming. B. The myosin heads conduct a power stroke motion to slide when bound to actin, to move the "thin" filaments towards the center of the sarcomere. C. During contraction, actin subunits are removed from the ends of the "thin" filaments to shorten actin polymers, thus reducing the length of the sarcomere. D. "Thick" filaments are anchored at the M-line, while "thin" filaments are anchored at the Z-line. E. Numerous myosin heads engage with the actin filaments simultaneously, such that there is no back-slipping during the contraction process.arrow_forwardWhat is the role of calcium in muscle contractions? Multiple Choice a) To spread the action potential through the T-tubules b) To bind with troponin, changing its shape so that binding sites on the actin filament are exposed c) To transmit the action potential across the neuromuscular junction d) To re-establish the polarization of the plasma's membrane following an action potential e) To break the cross-bridges as a cofactor in the hydrolysis of ATParrow_forwardWhich is a false statement about skeletal muscle structure?a. A myofibril is composed of multiple muscle fibers.b. Most skeletal muscles attach to bones by connective-tissue tendons.c. Each end of a thick filament is surrounded by six thin filaments.d. A cross-bridge is a portion of the myosin molecule.e. Thin filaments contain actin, tropomyosin, and troponin.arrow_forward
- When sarcomeres contract during muscle contraction, which of the following occurs? A. The myosin filaments lengthen. B. The myosin filaments "walk" along the actin microfilaments. C. The myosin filaments shorten. D. The actin filaments shorten.arrow_forwardOutline the role of calcium ions on muscle contraction during a biceps curl. In your answer: A) Describe the role of the nervous system in stimulating the release of calcium ions. b) Outline the role calcium ions play in the 'sliding filament theory?'arrow_forwardWhich of the following statements best describes the sliding filament mechanism of muscle contraction? a. Actin and myosin filaments do not shorten, but rather, slide past each other. b. Actin and myosin filaments shorten and slide past each other. c. As they slide past each other, actin filaments shorten, but myosin filaments do not shorten. d. As they slide past each other, myosin filaments shorten, but actin filaments do not shorten.arrow_forward
- Calmodulin is found in smooth muscle cells and performs a similar function to troponin in striated muscle fibers. However, calmodulin not only gets activated by Ca2+ but also slows the release of Ca2+ from the sarcoplasmic reticulum. How might this difference relate to the different kinds of contractions smooth muscles do in comparison to striated muscles?arrow_forwardThe function of Ca2+ in skeletal muscle contraction is toa. cause an allosteric change in myosin so it detaches from actin.b. provide the energy necessary for the movement of the cross-bridge.c. expose the myosin-binding sites on the thin filaments.d. bind to tropomyosin.e. do a and c only.arrow_forwardWhat would happen to muscle function if you ingested a toxin that completely inactivated troponin? The toxin inhibits its ability to change conformation. How would this affect muscle contraction?arrow_forward
- The sliding filament mechanism describes the process during which: a. actin and myosin slide relative to each other b. sarcomeres slide relative to each other c. troponin and tropomyosin slide relative to each other d. muscle fibers slide past each otherarrow_forwardUnlike skeletal muscle cells, cardiac muscle cells________." A do not use the sliding filament mechanism of contraction B are not striated C do not rely on an influx of Ca+2 for contraction to occur D do not require neural stimulation to contractarrow_forwardDuring the contraction of a vertebrate skeletal muscle fiber,calcium ions(A) break cross-bridges as a cofactor in hydrolysis of ATP.(B) bind with troponin, changing its shape so that the myosinbinding sites on actin are exposed.(C) transmit action potentials from the motor neuron to themuscle fiber.(D) spread action potentials through the T tubules.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning
Human Physiology: From Cells to Systems (MindTap ...
Biology
ISBN:9781285866932
Author:Lauralee Sherwood
Publisher:Cengage Learning
GCSE PE - ANTAGONISTIC MUSCLE ACTION - Anatomy and Physiology (Skeletal and Muscular System - 1.5); Author: igpe_complete;https://www.youtube.com/watch?v=6hm_9jQRoO4;License: Standard Youtube License