BIOLOGY:CONCEPTS+APPL.(LOOSELEAF)
10th Edition
ISBN: 9781305967359
Author: STARR
Publisher: CENGAGE L
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 32, Problem 2CT
After death, a person no longer makes ATP, so calcium stored in the sarcoplasmic reticulum diffuses down its concentration gradient into the muscle cytoplasm. This result is rigor mortis----an unbreakable state of muscle contraction that stiffens the body for a few days until muscles begin to decay. Explain why this contraction occurs.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Troponin C has been mutated such that it cannot bind to calcium.
Describe the effect of this mutation on sarcomere shortening in skeletal
muscle. A complete answer will describe the normal function of
troponin C, the normal process of sarcomere shortening, and will
describe the overall effect of the mutation on sarcomere shortening
based on troponin C's function and its role in the overall process of
sarcomere shortening.
After death, a person no longer makes ATP, and calcium stored in the specialized endoplasmic reticulum of muscle fibers diffuses down its concentration gradient into the muscle cytoplasm. The result is rigor mortis—an unbreakable state of muscle contraction. Explain why the contraction occurs and why it is irreversible.
1) Paula is a scientist who is developing a drug called Fremtol that will be used to treat muscle spasms. This drug acts on specific skeletal muscles to (1) block the release of Ca2+ ions from the sarcoplasmic reticulum, (2) inhibit the pivoting ability of the myosin heads of the thick filaments, and (3) block the production of ATP by the mitochondria in skeletal muscles. By using this drug, contraction of certain skeletal muscle fibers is reduced, which keeps those muscles from producing spasms.
In the above scenario, Fremtol’s effect of blocking the pivoting ability of the myosin heads of the thick filaments would have which of the following consequences?
a. decreased release of acetylcholine at the neuromuscular junction
b. inhibition of the power stroke
c. reduced production of myoglobin
d. All of the above
e. None of the above
2) Paula is a scientist who is developing a drug called Fremtol that will be used to treat muscle spasms. This drug acts on specific skeletal muscles to…
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
- As mentioned in class, one additional major use of ATP in skeletal muscle (besides powering the myosin heads) is the recycling of calcium ions back into the sarcoplasmic reticulum after depolarization. The resting concentration of Ca++ in the muscle cell cytoplasm is about 50-100 nM, and the spike concentration after depolarization is about 10-20 μΜ. a) Consider a single sarcomere. What is the number of free calcium ions within the sarcomere at rest? What is the number of free calcium ions after depolarization? b) The major ion pump responsible for calcium ion recycling is SERCA (sarco/endoplasmic reticulum calcium ATPase). SERCA uses one molecule of ATP to pump two calcium ions, and the resting level can be restored in about 10-20 ms. How many molecules of ATP are used in a single sarcomere for pumping calcium in a single "twitch"? c) Assume that a single "twitch" is sufficient to drive one sarcomere from its fully extended length (about 2.5 µm) to its fully contracted length (about 1…arrow_forward2) Paula is a scientist who is developing a drug called Fremtol that will be used to treat muscle spasms. This drug acts on specific skeletal muscles to (1) block the release of Ca2+ ions from the sarcoplasmic reticulum, (2) inhibit the pivoting ability of the myosin heads of the thick filaments, and (3) block the production of ATP by the mitochondria in skeletal muscles. By using this drug, contraction of certain skeletal muscle fibers is reduced, which keeps those muscles from producing spasms. In the above scenario, Fremtol’s effect of blocking the release of Ca2+ ions from the sarcoplasmic reticulum would most directly prevent which the following? a. activation of tropomyosin b. activation of troponin c. activation of actin d. All of the above e. None of the abovearrow_forwardImpairment of intracellular calcium homeostasis in muscle fibers lead to chronic, severe muscle dysfunction. Impaired Calcium ATPase activity can lead to abnormal, persistent elevation of intracellular calcium concentrations. Explain how persistently high intracellular calcium concentration would affect cross-bridge formation, and muscle contractions, and muscle tension? (Mention the effects on the steps involved cross bridge formation, and muscle contraction/relaxation cycle, and overall muscle tension).arrow_forward
- You are a brilliant (but evil) biochemist who is developing a toxin that can be used to paralyze skeletal muscle. Using your knowledge of the sequence of cellular/molecular events that cause a muscle contraction, identify two parts of the process that could be disrupted to cause paralysis, and explain the specific effect of each disruption on contraction. please helparrow_forwardIn 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.arrow_forwardPlease answer all questions Following death, muscles enter a period of sustained contraction called rigor mortis. This develops because: a) the Na+/K+ active transport pump fails. b) there isn't any more neurotransmitter secretion. c) there isn't any ATP to break actin-myosin bonds. d) calcium is not returned to the cisternae. If a muscle is stimulated to contract at maximum tension yet brief periods of relaxation are possible, the muscle is demonstrating: a) twitch. b) summation. c) incomplete tetany. d) complete tetany.arrow_forward
- 3) Paula is a scientist who is developing a drug called Fremtol that will be used to treat muscle spasms. This drug acts on specific skeletal muscles to (1) block the release of Ca2+ ions from the sarcoplasmic reticulum, (2) inhibit the pivoting ability of the myosin heads of the thick filaments, and (3) block the production of ATP by the mitochondria in skeletal muscles. By using this drug, contraction of certain skeletal muscle fibers is reduced, which keeps those muscles from producing spasms. In the above scenario, Fremtol’s effect of blocking muscle mitochondrial ATP production would result in the inability of the muscle to make ATP from ___________. a. creatine phosphate b. anaerobic glycolysis c. aerobic respiration d. All of the above e. None of the abovearrow_forwardPluripotent stem cells undergo a number of changes as they progress through developmental stages to become the terminally differentiated cell type known as a skeletal muscle myofiber. a) Describe the stages and key anatomic and functional changes that occur during differentiation of myofibers. b) Despite the fact that myofibers are terminally differentiated, muscle can regenerate itself following a trauma or injury. Describe how this can occur.arrow_forwardOne of the primary characteristics of all muscle tissue is contractility, the ability to shorten (contract) and lengthen (relax). You've identified the various components of a myofibril above. Now, use the table below to indicate what occurs to each band, line, or zone when the muscle contracts vs. relaxes. What occurs to this region / structure during contraction/relaxation? Region / Structure A-Band H-Band I-Band M-Line Z-Line Zone of Overlap Sarcomere No change Shortens Lengthens Muscle Contraction Muscle Relaxationarrow_forward
- Cardiac and skeletal muscle are both “striated” types of muscle and yet they have very distinct functional characteristics. a) Skeletal muscle functions as discrete motor units and the cardiac muscle works as a functional syncytium. Define the italicized terms in the previous sentence, explain their importance, and describe the cellular features that underlie these functional differences. b) Cardiac muscle exhibits automaticity, while excitation of skeletal muscle is neurogenic. Define the italicized terms and provide a brief explanation of mechanisms underlying each.arrow_forwardWhether the statement, "Motor neurons trigger action potentials in muscle cell membranes that open voltage-sensitive Ca2+ channels in T tubules, allowing extracellular Ca2+ to enter the cytosol, bind to troponin C, and initiate rapid muscle contraction", is true or false.arrow_forwardSkeletal muscle has several distinct fiber types. Type I is used primarily for aerobic activity, whereas type IIb is specialized for short, intense bursts of activity. How could you distinguish between these types of muscle fiber if you viewed them with an electron microscope?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
Necrosis vs. Apoptosis: Cell Death; Author: AMBOSS: Medical Knowledge Distilled;https://www.youtube.com/watch?v=zFrBwGfOQs0;License: Standard Youtube License