19. Which of the following statements about actin is true? A. Binding of actin filaments by ARPS promotes disassembly of actin filaments. B. Actin treadmilling occurs at high concentrations of actin. C. Focal adhesions are released at the beginning of cell movement and do not reform until the cell has reached its destination. D. Actin polymerization initiates protrusion of the membrane in lamellipodia and filopodia.

19. Which of the following statements about actin is true? A. Binding of actin filaments by ARPS promotes disassembly of actin filaments. B. Actin treadmilling occurs at high concentrations of actin. C. Focal adhesions are released at the beginning of cell movement and do not reform until the cell has reached its destination. D. Actin polymerization initiates protrusion of the membrane in lamellipodia and filopodia.

Biology 2e

2nd Edition

ISBN:9781947172517

Author:Matthew Douglas, Jung Choi, Mary Ann Clark

Publisher:Matthew Douglas, Jung Choi, Mary Ann Clark

Chapter4: Cell Structure

Section: Chapter Questions

Problem 20RQ: Which of the following do not play a role in intracellular movement? microfilaments and intermediate...

See similar textbooks

Similar questions

3. The protein integrin binds to actin filaments and, by binding to proteins like fibronectins, connects to collagen. In this manner, integrin ______. A.controls the permeability of the cytoplasmic membrane B. suspends organelles within the cytoplasm C. provides a direct linkage between the cytoskeleton and the extracellular matrix D. helps keep individual cells in place and connects adjacent cells to each other
Actin and microtubules have polarity, intermediate filaments have no polarity. What is the main consequence of this difference?
1. Calcium triggers the contraction of a muscle fiber. Where in the muscle fiber is this calcium stored? A. nucleus B. calcium vesicles C. sarcoplasmic reticulum D. Golgi apparatus E. mitochondria
1. When considering tight junctions, adherens junctions, and desmosomes: a. Which ones do not help in resisting mechanical stress and holding cell shape? Why not? b. Considering how the mechanical junctions are placed in the plasma membrane, why don’t they provide a truly sealed barrier?
Which of the following are differences between the assembly processes of intermediate filaments versus that of actin microfilaments? A. New subunits are added internally to the intermediate filament rather than at the ends B. Assembly requires GTP rather than ATP C. Intermediate filaments are assembled from multiple tetramers rather than from monomers. D. A and B E. A and C
Which of the following do not play a role in intracellular movement? microfilaments and intermediate filaments microfilaments and microtubules intermediate filaments and microtubules only intermediate filaments
Which of the following means the ability to transmit electrical current from one cell to another? A. Conductivity B. Excitability C. Contractility D. Automaticity
The cells of muscles, myocytes, develop from ________. myoblasts endoderm fibrocytes chondrocytes
20.The thick filament is composed almost entirely of _____ molecules. (This is a multiple choice question choose the answer from the choices below) A.myosin B.actin C.tropomyosin D.thrombin
1. Name the two types of structures that mediate cell-cell contact and are associated with intermediate filaments. 2. The dynamic behavior of microtubules is regulated by a variety of MAPs. What does this stand for? 3. Name the two motor proteins responsible for powering the variety of movements
5. Which of the following is NOT true of formins and Arp2/3 nucleators? Group of answer choices A. They are involved actin filament assembly B. They are the rate-limiting step of actin polymerization C. They are both actin-nucleating proteins D. They both assemble long actin filaments E. They are both controlled by signal transduction pathways
There 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.