Concept explainers
If myosin V moved more like an “inchworm” (meaning it dragged its rear filament-binding domain forward, but not in a hand-over-hand fashion), how would a graph of spot movement over time differ from the one shown in Figure 14A-2b?
To determine: The way in which graph of spot movement over time differs from the graph shown in figure 14A-2b given in the textbook when myosin V moved like an inchworm.
Introduction: Myosin protein V is an important protein which is involved in the transports of various types of intracellular cargo along with actin proteins. These myosin proteins are involved in the transport of various membrane-bound organelles and show two alternating types of mechanisms for movement. One method is the hand-over-hand method and another method is the inch worm model.
Explanation of Solution
Hand-over-hand mechanism of myosin V movement states that the trailing head would move past the stationary forward head by an approximate distance of 74 nanometers to reach a new actin binding site. In contrast to this, the inch-worm model suggests that both heads would advance or move forward only by 37 nanometers during the step. Both trailing and leading heads do not undergo the process of position exchange during the inch worm model.
The best way to determine the difference between the hand-over-hand model and inch-worm models is to strictly follow the displacement of one of myosin V heads. Therefore, a graph of spot movement over time will differ in case of distance as 74 nanometers (position along actin filament) will be shown in the hand-over-hand model and 35 nanometers will be shown in inchworm model of spot movement.
Want to see more full solutions like this?
Chapter 14 Solutions
Becker's World of the Cell (9th Edition)
- Which of the following molecular motors is known to travel in an anterograde direction along microtubules? myosins kinesins myosins and dyneins dyneinsarrow_forwardYou are growing up myoblasts, C2C12 cells, to use in a myogenic study. You are using T-150 flasks with a culture area of 150 cm2 and when confluent contains 2 x 107 cells.You are growing up myoblasts 3)You seed another culture of a different end cell line, john12 cells at 8am on Friday with 104 cells. By Thursday at noon (12:00pm) they reach confluence. Assume the same confluency as stated above for T150 flask. What is the generation time (doubling time)arrow_forwardMy question is how many myosin binding sites are uncovered or exposed per binding of calium ions to one troponin complex in particular TnCarrow_forward
- What ion is necessary for movement of the troponintropomyosin complex? What is the role of thesarcoplasmic reticulum in this process?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_forwardCofilin preferentially binds to older actin filamentsand promotes their disassembly. How does cofilin distin-guish old filaments from new ones?arrow_forward
- Actin filaments at the leading edge of a crawling cell are believed to undergo treadmilling. What is treadmilling, and what accounts for this assembly behavior?arrow_forwardThe main structural characteristic of myosin molecules is: Select one: a. A beta-barrel b. A Fab domain c. An alpha helix d. The zinc finger domain e. A beta sheetarrow_forwardThere are no known motor proteins that move along intermediate filaments, in contrast to the variety of such proteins that associate with microtubules and actin filaments. What characteristic of intermediate filaments, in their polymerized form, might explain the absence of associated motor proteins? Briefly explain your reasoning.arrow_forward
- . Salmon are anadromous fish and must deal with osmotic changes in their environment in extreme ways. Researchers have found that Na*/K* - ATPase is found in two different kinds of cells in the gill tissue. One type is found in the filament bases that appear to be active when salmon are adults only. The other types of cells are found in the lamellae folds and appear to be active during its juvenile stages. Speculate on these findings as to how this allows salmon to complete their unique life cycle.arrow_forwardhow would myosin arrange the actin such that a virus could not enter the cell?arrow_forwardDo flexable adapter molecules not play a part in this?arrow_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage LearningBiology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage Learning