Becker's World of the Cell (9th Edition)
9th Edition
ISBN: 9780321934925
Author: Jeff Hardin, Gregory Paul Bertoni
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
Chapter 14, Problem 14.4CC
Summary Introduction
To determine: The reason that the movement of heavy chains of myosin in thick filaments always results in the contraction of the sarcomere.
Introduction: Myosins are made up of two heavy chains that possess a globular domain, a hinge, a long rod-like tail, and a total of four light chains. In these proteins, one essential light chain and one regulatory light chain are always associated with each heavy chain.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
What prevents the filaments from sliding back to their original position each time a myosin cross bridge detaches from actin?
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?
Shortly after a person dies, Calcium ions diffuse out of the sarcoplasmic reticulum and the body becomes very stiff and rigid, a phenomenon called rigor mortis (stiffness + death). Given ATP’s role in myosin head movement, propose an explanation for rigor mortis.
Chapter 14 Solutions
Becker's World of the Cell (9th Edition)
Ch. 14 - If myosin V moved more like an inchworm (meaning...Ch. 14 - Kinesins and dyneins are both microtubule-based...Ch. 14 - CONCEPT CHECK 14.2 Human sperm swim using a...Ch. 14 - A single myosin II motor domain can exert about 15...Ch. 14 - Prob. 14.4CCCh. 14 - In addition to being found at the rear of...Ch. 14 - Ciliobrevins. Ciliobrevins were reported in 2012...Ch. 14 - Prob. 14.2PSCh. 14 - Prob. 14.3PSCh. 14 - Rigor Mortis and the Contraction Cycle. After...
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
- A 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_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_forwardYou know from experience that skeletal muscle tires quite quickly, especially if there is not enough oxygen. Interestingly, shellfish such as clams can maintain a month-long contraction in the muscle that keeps the shell closed. No oxygen gets in this situation. These muscles have a different version of myosin called paramyosin. Knowing what you know about the cellular mechanism of muscle contraction, propose a hypothesis to explain how paramyosin might work.arrow_forward
- 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.arrow_forwardWith 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_forwardA typical relaxed sarcomere is about 2.3 um in length and contracts to about 2 um 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 con- tracted sarcomere. (b) An individual "step" by a myosin head in one cycle pulls the thin fila- ment about 15 nm. How many steps must each actin fiber make in one contraction?arrow_forward
- In the sliding filament theory of contraction, what prevents the filaments from sliding back to their original positions each time a myosin head releases to bind to next actin binding site?arrow_forwardHow many actin monomers within an actin filament would a myosin molecule need to ratchet in order to contract a cell by approximately 1 μm?arrow_forwardIf you were to watch muscle tissue contract: Under a light microscope, would you see the muscle fibers get narrower, or the striations get thinner? Explain. At the EM level, focusing on one sarcomere, you would be able to see a region of thick filaments overlapping two regions of thin filaments. Use the structure of the thick filaments to explain how ONE region of thick filaments is able to pull in microfilament in two opposite directions (both toward the center of the sarcomere).arrow_forward
- A typical relaxed sarcomere is about 2.3 μm in length and contracts to about2 μm in length. Within the sarcomere, the thin filaments are about 1 μmlong and the thick filaments are about 1.5 μm 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 filamentabout 15 nm. How many steps must each actin fiber make in one contraction?arrow_forwardsince sarcomeres within skeletal muscles are rigidly aligned with each other what do you think excessive stretch or compression (remember the basic structure of the sarcomere with overlapping thin and thick filaments and the length-tension relationship) will do to the force generation of a muscle contraction?arrow_forwardChoose the best description of how myosin and actin are arranged within the two types of protein filaments in myofibrils. a.) Actin makes up the think filaments, and myosin makes up the thin filaments. b.) Myosin makes up the think filaments, and actin makes up the thin filaments. c.) Myosin and actin are randomly interspersed in the think filaments but are absent from the thin filaments. d.) Myosin and actin overlap with each other to make up both the think and thin filaments.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