Loose Leaf For Integrated Principles Of Zoology
18th Edition
ISBN: 9781260411140
Author: Cleveland P Hickman Jr. Emeritus, Susan L. Keen, David J Eisenhour Professor PhD, Allan Larson, Helen I'Anson Associate Professor of Biology
Publisher: McGraw-Hill Education
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
Chapter 29, Problem 14RQ
Summary Introduction
To explain: The way by which an electron micrograph shows that during constriction, the actin and myosin filaments persist constant length while the distance between the Z lines shortens.
Introduction: Muscle constricts in response to the stimulation of a nerve. The striated muscle shows periodic bands, plainly visible under a light microscope. Each striated muscle cell is tube-shaped and multinucleated. It is made up of myofibrils and sarcolemma. Myofibrils are made up of actin and myosin.
Summary Introduction
To explain: The role regulatory proteins troponin and tropomyosin.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Certain multi-headed myosins bind cooperatively to actin filaments. The binding interaction is mainly electrostatic in nature, so the presence of additional salt (ions) in solution can interfere with binding; ions will tend to associate with charged residues on the two proteins, blocking electrostatic attractions that would otherwise take place. Briefly describe the expected shape of the binding curve for one of these myosins, and what will happen to the shape when the salt concentration increases.
The sliding-filament model of skeletal-muscle contraction assumes a sliding or slipping of interdigitating filaments of actin and myosin. Electron micrographs show that during contraction the actin and my-osin filaments remain of constant length while the distance between Z lines shortens. Explain how this happens in terms of the molecular structure of the muscle filaments. What is the role of regulatory pro-teins (troponin and tropomyosin) in contraction?
Describe the movement of myosin along an actin filament. Outline the primary molecular steps and explain how this process is used by cells. How many actin monomers within an actin filament would a myosin molecule need to ratchet in order to contract a cell by approximately 1 um? How fast could a non-muscle cell make this contraction compared to a muscle cell if the relative rates of myosin walks on F-actin are 4.5 um/sec and 0.04 um/sec for myosin II and I respectively?
Chapter 29 Solutions
Loose Leaf For Integrated Principles Of Zoology
Ch. 29 - The arthropod exoskeleton is the most complex of...Ch. 29 - Distinguish between epidermis and dermis in...Ch. 29 - Prob. 3RQCh. 29 - As naked apes humans lack the protective...Ch. 29 - Prob. 5RQCh. 29 - Prob. 6RQCh. 29 - What is the difference between endochondral and...Ch. 29 - Discuss the role of osteoclasts, osteoblasts,...Ch. 29 - The laws of scaling tell us that doubling the...Ch. 29 - Prob. 10RQ
Ch. 29 - Prob. 11RQCh. 29 - Prob. 12RQCh. 29 - What functional features of molluscan smooth...Ch. 29 - Prob. 14RQCh. 29 - While the sarcoplasmic reticulum of muscle was...Ch. 29 - The filaments of skeletal muscle are moved by free...Ch. 29 - During evolution, skeletal muscle became adapted...Ch. 29 - A weight lifter decides to go jogging with a...
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_forwardThe ability of myosin to walk along an actin filament may be observed with the aid of an appropriately equipped microscope. Describe how such assays are typically performed. Why is ATP required in these assays? How can such assays be used to determine the direction of myosin movement or the force produced by myosin?arrow_forwardSkeletal muscle cells undergo contractions based on a molecular mechanism involving: 1)the sliding of actin and myosin filaments past each other without any change in filament length 2) the shortening of actin filaments following direct interaction with myosin 3) dynamic instability of microtubules 4)nonearrow_forward
- Myosin II has a duty ratio of 10 percent, and its step size is 8 nm. In contrast, myosin V has a much higher duty ratio (about 70 percent) and takes 36-nm steps as it walks down an actin filament. What differences between myosin II and myosin V account for their different properties?arrow_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_forwardWhat is the main order histological structure of sarcomere? * Z line bind with actine without interaction with myosin Interaction of actine and myosin with Z line Interaction of myosin and actine with Z line Interaction of Z line with myosin and actinearrow_forward
- For the skeletal muscle, hydrolyzation of ATP: Group of answer choices At the myosin head gives rise to the generation of power stroke. At the actin G-molecule gives rise to the generation of power stroke. At the myosin head give rise to the rotation of myosin head to the "cocked back" position. At the actin G-molecule give rise to the rotation of myosin head to the "cocked back" position.arrow_forwardDuring the cross-bridge in muscle cells, myosin motors hydrolyzes ATP as a fuel to create a pulling force on actin fibers. Please describe1) the myosin motors undergo different steps of ATP hydrolysis2) the state of the ATP nucleotide affects the binding and position of the myosin motor with respect to the actin fiberarrow_forwardDescribe the contraction of a muscle fiber, starting with what events take place at the neuromuscular junction, explaining how depolarization along the length of the sarcolemma occurs, the role of calcium (where it is released, what it binds to, etc.), and the events that occur after calcium binds to troponin. Draw a few simple, labelled diagrams of a neuromuscular junction and sarcomere and outline the steps of excitation-contraction coupling, including power stroke, recovery stroke, formation of cross bridges, role of ATP, etc.arrow_forward
- 1. a) Why are muscles not in a contracted state all the time? b) Several hours after the death of an animal, a state of rigor mortis, extreme rigidity of the body, occurs. With respect to myosin and actin filaments, why does this occur? What causes the body to relax more later in time? Explain.arrow_forwardA typical relaxed sarcomere is about 2.3 µm in length and contracts to about 2 µm in length. Within the sarcomere, the thin filaments are about 1 um long and the thick filaments are about 1.5 um long. (a) Describe the overlap of thick and thin filaments in the relaxed and contracted sarcomere. (b) An individual "step" by a myosin head in one cycle pulls the thin filament about 15 nm. How many steps must each actin fiber make in one contraction?arrow_forwardThank youarrow_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