Cell Biology: Cytoskeleton Overview
155 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

The cytoskeleton is a network of fibers extending throughout the ______.

cytoplasm

The cytoskeleton is composed of three types of molecular structures: Microtubules, Microfilaments, and ______.

Intermediate filaments

The cytoskeleton helps to support the cell and maintain its ______.

shape

Inside the cell, vesicles can travel along 'monorails' provided by the ______.

<p>cytoskeleton</p> Signup and view all the answers

The cytoskeleton is an essential component of the cell ______ machinery.

<p>division</p> Signup and view all the answers

Microtubules participate in a wide variety of cell ______.

<p>activities</p> Signup and view all the answers

The cytoskeleton may help regulate biochemical ______.

<p>activities</p> Signup and view all the answers

One function of the cytoskeleton is to provide structural ______.

<p>support</p> Signup and view all the answers

Protein motors use ______ to provide motion.

<p>ATP</p> Signup and view all the answers

______ are responsible for the migration of chromosomes during mitosis and meiosis.

<p>Microtubules</p> Signup and view all the answers

GTP hydrolysis controls the dynamic ______ of microtubules.

<p>instability</p> Signup and view all the answers

Microtubules grow and shrink ______ of their neighbors.

<p>independently</p> Signup and view all the answers

Microtubule-binding proteins are known as ______.

<p>MAPs</p> Signup and view all the answers

Kinesins are motor proteins that transport materials along ______ in the nerve axon.

<p>microtubules</p> Signup and view all the answers

MAPs can prevent or promote cytosolic microtubule ______.

<p>polymerization</p> Signup and view all the answers

Microtubules guide the transport of organelles, vesicles, and ______.

<p>macromolecules</p> Signup and view all the answers

Actin polymerization involves ATP hydrolysis instead of ______.

<p>GTP</p> Signup and view all the answers

Actin-binding proteins (ABPs) include banding and cross linking proteins, regulatory proteins, and ______ proteins.

<p>motor</p> Signup and view all the answers

Actin filaments are often nucleated at the ______ membrane.

<p>plasma</p> Signup and view all the answers

Actin associates with thicker filaments made of the motor protein ______.

<p>myosin</p> Signup and view all the answers

Myosin-I is considered the simplest form of ______.

<p>myosin</p> Signup and view all the answers

Cytoplasmic dyneins attached to Golgi membranes pull the Golgi along ______ toward the nucleus.

<p>microtubules</p> Signup and view all the answers

Muscles contract by a sliding-______ mechanism.

<p>filament</p> Signup and view all the answers

Myosin-II molecules can associate with one another to form myosin-______ filaments.

<p>II</p> Signup and view all the answers

Kinesins and cytoplasmic dyneins are ______ motor proteins that move in opposite directions along the microtubules.

<p>MT</p> Signup and view all the answers

In muscle cells, thousands of actin filaments are arranged ______ to one another.

<p>parallel</p> Signup and view all the answers

The bending of cilia and flagella is driven by the arms of a motor protein called ______.

<p>dynein</p> Signup and view all the answers

______ filaments are important for providing mechanical strength to the cell and are involved in various cellular functions.

<p>Actin</p> Signup and view all the answers

G actin monomers polymerize into ______ filaments.

<p>F-actin</p> Signup and view all the answers

Actin subunits assemble head to tail to generate filaments with structural ______.

<p>polarity</p> Signup and view all the answers

Microfilaments resist ______ and form a three-dimensional network just inside the plasma membrane.

<p>tension</p> Signup and view all the answers

______ interacts with myosin to provide the force of muscular contraction.

<p>Actin</p> Signup and view all the answers

Intermediate filaments provide mechanical strength and resistance to ______.

<p>shear stress</p> Signup and view all the answers

Keratins are found in epithelial cells, hair and ______.

<p>nails</p> Signup and view all the answers

Nuclear lamins form a meshwork that stabilizes the inner ______ membrane.

<p>nuclear</p> Signup and view all the answers

Neurofilaments strengthen the long axons of ______.

<p>neurons</p> Signup and view all the answers

Vimentins provide mechanical strength to ______ and other cells.

<p>muscle</p> Signup and view all the answers

Intermediate filaments are ______ in size at 8 - 12 nanometers.

<p>intermediate</p> Signup and view all the answers

Drugs that inhibit ______ are used in biomedical research.

<p>microfilaments</p> Signup and view all the answers

Taxol binds and stabilizes ______.

<p>microtubules</p> Signup and view all the answers

Lamin and cell-specific proteins are key components of ______ filaments.

<p>intermediate</p> Signup and view all the answers

Skin diseases like epidermolysis bullosa are associated with mutations in genes encoding ______ proteins.

<p>cytoskeletal</p> Signup and view all the answers

The cytoskeleton provides ______ to maintain the shape of the cell.

<p>support</p> Signup and view all the answers

Motor proteins interact with the cytoskeleton to produce ______.

<p>motility</p> Signup and view all the answers

The ______ consists of microtubules, microfilaments, and intermediate filaments.

<p>cytoskeleton</p> Signup and view all the answers

Microtubules are involved in intracellular ______ and the movement of organelles.

<p>transport</p> Signup and view all the answers

The bending of ______ and flagella is driven by motor proteins.

<p>cilia</p> Signup and view all the answers

Actin filaments can resist ______ and are involved in maintaining cell shape.

<p>tension</p> Signup and view all the answers

Intermediate filaments provide ______ strength to cells.

<p>mechanical</p> Signup and view all the answers

Vimentins are types of intermediate filaments that provide strength to ______ cells.

<p>mesenchymal</p> Signup and view all the answers

Cilia and flagella contain stable microtubules moved by ______.

<p>dynein</p> Signup and view all the answers

Some functions of actin filaments include providing mechanical strength and generating ______ in cells.

<p>locomotion</p> Signup and view all the answers

The actin subunit, which is a monomer, has a binding site for a nucleotide such as ATP or ______.

<p>ADP</p> Signup and view all the answers

During cytokinesis in animal cells, actin filaments form a ______ ring.

<p>contractile</p> Signup and view all the answers

Cytoplasmic dyneins transport materials ______ from the Golgi apparatus.

<p>inward</p> Signup and view all the answers

The bending motion of cilia is driven by the interaction of dynein with ______.

<p>microtubules</p> Signup and view all the answers

G actin monomers polymerize to form ______ filaments.

<p>F-actin</p> Signup and view all the answers

Actin and myosin interaction provides the force for ______ contraction.

<p>muscular</p> Signup and view all the answers

The migration of chromosomes during mitosis and meiosis takes place on ______ that make up the spindle fibers.

<p>microtubules</p> Signup and view all the answers

Each microtubule grows and shrinks independently of its ______.

<p>neighbors</p> Signup and view all the answers

Microtubule-binding proteins (MAPs) organize microtubules and affect their ______.

<p>stability</p> Signup and view all the answers

Kinesins bind to the Endoplasmic ______, stretching it along microtubules.

<p>reticulum</p> Signup and view all the answers

GTP hydrolysis controls the dynamic instability of ______.

<p>microtubules</p> Signup and view all the answers

Cytoplasmic dyneins pull the Golgi along microtubules toward the ______.

<p>nucleus</p> Signup and view all the answers

Actin polymerization is similar to tubulin MT but involves ATP hydrolysis instead of __________.

<p>GTP</p> Signup and view all the answers

Actin binding proteins include banding and cross linking proteins, regulatory proteins, and __________ proteins.

<p>motor</p> Signup and view all the answers

The highest density of actin filaments in most cells is at the cell __________.

<p>periphery</p> Signup and view all the answers

Actin associates with thicker filaments composed of the motor protein __________.

<p>Myosin</p> Signup and view all the answers

Myosin-I has a globular head that attaches to actin filaments and a tail that attaches to __________.

<p>vesicles</p> Signup and view all the answers

Myosin-II molecules can associate with one another to form __________ filaments.

<p>myosin-II</p> Signup and view all the answers

Muscles contract by a __________-filament mechanism.

<p>sliding</p> Signup and view all the answers

What role does the cytoskeleton play in cell motility?

<p>It interacts with motor proteins to facilitate movement.</p> Signup and view all the answers

Which type of cytoskeletal structure is primarily responsible for maintaining cell shape and polarity?

<p>Intermediate filaments</p> Signup and view all the answers

Which of the following is NOT a documented function of the cytoskeleton?

<p>Transporting neurotransmitters</p> Signup and view all the answers

How does the cytoskeleton contribute to intracellular transport?

<p>By providing pathways that vesicles can travel along</p> Signup and view all the answers

Microtubules play a significant role during which of the following processes?

<p>Cell division</p> Signup and view all the answers

What is one way that the cytoskeleton helps in intracellular transport?

<p>It acts as a scaffold for organelles.</p> Signup and view all the answers

Which of the following correctly describes a feature of microtubules?

<p>They can grow and shrink dynamically, responding to the cell’s activities.</p> Signup and view all the answers

Which cytoskeletal structure is associated with the motility of cilia and flagella?

<p>Microtubules</p> Signup and view all the answers

What type of proteins are responsible for regulating the organization of actin filaments?

<p>Actin-binding proteins</p> Signup and view all the answers

Which myosin is considered the simplest form of myosin?

<p>Myosin-I</p> Signup and view all the answers

Where is the highest density of actin filaments typically found in most cells?

<p>Cell periphery</p> Signup and view all the answers

Which of the following describes the interaction of myosin-II molecules?

<p>They can associate to form myosin-II filaments.</p> Signup and view all the answers

What mechanism do muscles use for contraction?

<p>sliding-filament mechanism</p> Signup and view all the answers

Which actin-associated process involves ATP hydrolysis?

<p>Actin polymerization</p> Signup and view all the answers

What type of proteins slide on microfilaments to mediate contraction?

<p>Motor proteins</p> Signup and view all the answers

What structural feature allows muscles to contract effectively using actin and myosin?

<p>Interdigitation of actin fibers</p> Signup and view all the answers

What is the primary function of dynein in relation to the Golgi apparatus?

<p>To pull the Golgi inward toward the nucleus</p> Signup and view all the answers

Which statement about actin filaments is NOT true?

<p>Actin filaments are rigid structures that do not change shape.</p> Signup and view all the answers

Which property allows microtubules to resist tension?

<p>Their rigid and stable structure</p> Signup and view all the answers

What is the role of myosin in relation to actin filaments?

<p>To generate force for muscle contraction</p> Signup and view all the answers

How do cilia and flagella achieve their bending motion?

<p>Through the action of dynein motor proteins</p> Signup and view all the answers

Which function is NOT performed by microfilaments?

<p>Transporting materials along microtubules</p> Signup and view all the answers

What is the primary building block of microfilaments?

<p>Actin monomers</p> Signup and view all the answers

Which of the following statements correctly describes motor proteins?

<p>They transport cellular cargo along cytoskeletal filaments.</p> Signup and view all the answers

What is the primary function of microtubules within the cell?

<p>To guide the transport of organelles and vesicles</p> Signup and view all the answers

How do microtubule-binding proteins (MAPs) affect microtubule dynamics?

<p>They organize microtubules and influence their stability.</p> Signup and view all the answers

What energy molecule do protein motors use for movement?

<p>ATP</p> Signup and view all the answers

What role does GTP hydrolysis play in the behavior of microtubules?

<p>It regulates the dynamic instability of microtubules.</p> Signup and view all the answers

What are kinesins responsible for during intracellular transport?

<p>Transporting the endoplasmic reticulum along microtubules</p> Signup and view all the answers

What characterizes microtubules compared to other cytoskeletal components?

<p>They grow and shrink independently of one another.</p> Signup and view all the answers

Which of the following statements about the transport along microtubules is incorrect?

<p>Microtubules exclusively support transport of only vesicles.</p> Signup and view all the answers

Which proteins are involved in organizing microtubules into bundles?

<p>Microtubule-associated proteins (MAPs)</p> Signup and view all the answers

What is the primary function of intermediate filaments in cells?

<p>Provide mechanical strength and resistance to shear stress</p> Signup and view all the answers

Which type of intermediate filament is found in epithelial cells, hair, and nails?

<p>Keratins</p> Signup and view all the answers

What is the structure formed when two dimers align laterally in intermediate filament assembly?

<p>Tetrameric protofilament</p> Signup and view all the answers

How thick are intermediate filaments compared to other cytoskeletal structures?

<p>8-12 nanometers</p> Signup and view all the answers

Which disease is associated with mutations in genes encoding intermediate filament proteins?

<p>Epidermolysis bullosa</p> Signup and view all the answers

What mechanism is primarily involved in the assembly of intermediate filaments?

<p>End-to-end and side-to-side alignment</p> Signup and view all the answers

What role do neurofilaments serve in neurons?

<p>Strengthening axons</p> Signup and view all the answers

Which of the following is NOT a type of intermediate filament?

<p>Actin</p> Signup and view all the answers

Which statement accurately describes the stability of intermediate filaments?

<p>They are permanent fixtures of the cytoskeleton.</p> Signup and view all the answers

What is the largest class of eukaryotic cytoskeletal structures?

<p>Microtubules</p> Signup and view all the answers

What process does myosin-I utilize to interact with actin filaments?

<p>ATP hydrolysis</p> Signup and view all the answers

Which actin-binding protein category is tasked with controlling the dynamics of polymerization and depolymerization?

<p>Regulatory proteins</p> Signup and view all the answers

How are the highest concentrations of actin filaments organized within a cell?

<p>At the plasma membrane</p> Signup and view all the answers

What occurs when myosin-II molecules associate with each other?

<p>They create myosin-II filaments</p> Signup and view all the answers

What type of structure is formed by the sliding movement of myosin along actin filaments?

<p>Contractile structures</p> Signup and view all the answers

Which of the following statements about actin polymerization is true?

<p>It relies on ATP hydrolysis.</p> Signup and view all the answers

What role do capping proteins play in the organization of actin filaments?

<p>They stabilize filament ends to prevent further growth.</p> Signup and view all the answers

What structural arrangement do thousands of actin filaments achieve in muscle cells?

<p>Parallel alignment</p> Signup and view all the answers

What role do microtubules play during the process of mitosis and meiosis?

<p>They act as tracks for chromosome migration.</p> Signup and view all the answers

How do microtubule-binding proteins (MAPs) influence microtubules?

<p>They stabilize microtubules against depolymerization.</p> Signup and view all the answers

What is the significance of GTP hydrolysis in microtubule dynamics?

<p>It decreases the stability of microtubules.</p> Signup and view all the answers

Which motor protein is responsible for positioning organelles within the cell and stretching the endoplasmic reticulum?

<p>Kinesin</p> Signup and view all the answers

What characteristic is true regarding the growth and shrinkage of microtubules?

<p>Each microtubule grows and shrinks independently of others.</p> Signup and view all the answers

What is one of the roles of microtubules in intracellular transport?

<p>Facilitating transport of organelles and vesicles in both directions.</p> Signup and view all the answers

What structural advantage do microfilaments have in a cell?

<p>They form a three-dimensional network just inside the plasma membrane.</p> Signup and view all the answers

Which of the following correctly describes the function of dynein in cilia and flagella?

<p>It allows for bending movement by pulling on adjacent microtubules.</p> Signup and view all the answers

Which of the following statements about the dynamic nature of microtubules is true?

<p>Microtubule stability is influenced by MAPs and GTP hydrolysis.</p> Signup and view all the answers

How do actin subunits contribute to the dynamic nature of microfilaments?

<p>They undergo polymerization and depolymerization through ATP hydrolysis.</p> Signup and view all the answers

How do Kinesins and Dyneins differ in their function within the cell?

<p>Kinesins generally move toward the plus end of microtubules, while Dyneins move toward the minus end.</p> Signup and view all the answers

What is the role of the tail domain in dynein and kinesin motor proteins?

<p>It binds to the motor protein's cargo.</p> Signup and view all the answers

Which statement correctly describes the assembly of actin filaments?

<p>F-actin is formed through head-to-tail assembly of monomers.</p> Signup and view all the answers

What distinguishes kinesins from dyneins in their function?

<p>Kinesins typically move toward the cell periphery, whereas dyneins move toward the nucleus.</p> Signup and view all the answers

What is the mechanism by which microfilaments contribute to cytokinesis in animal cells?

<p>They form a contractile ring that pinches the cells apart.</p> Signup and view all the answers

What is the primary function of the arms of dynein motor proteins in cilia?

<p>To coordinate the beating of cilia for fluid movement.</p> Signup and view all the answers

What is the primary role of intermediate filaments in the cytoskeleton?

<p>Providing mechanical strength and resistance to shear stress</p> Signup and view all the answers

Which type of intermediate filament is specifically associated with epithelial cells, hair, and nails?

<p>Keratins</p> Signup and view all the answers

How many protofilaments make up a fully assembled intermediate filament?

<p>Eight</p> Signup and view all the answers

Which condition is NOT associated with mutations in genes encoding intermediate filaments?

<p>Lissencephaly</p> Signup and view all the answers

Which protein type is responsible for reinforcing the long axons of neurons?

<p>Neurofilaments</p> Signup and view all the answers

What size range do intermediate filaments fall into?

<p>8 - 12 nanometers</p> Signup and view all the answers

Which of the following drugs is specifically known to inhibit microtubules?

<p>Taxol</p> Signup and view all the answers

Vimentins are types of intermediate filaments that primarily provide mechanical strength to which type of cells?

<p>Mesenchymal cells</p> Signup and view all the answers

Which of these statements about the assembly of intermediate filaments is true?

<p>Protofilaments are formed by the lateral alignment of dimers.</p> Signup and view all the answers

Which type of intermediate filament is formed from proteins characteristic of nuclear structure?

<p>Nuclear lamins</p> Signup and view all the answers

What is one of the primary roles of the cytoskeleton in relation to cell division?

<p>It aids in the distribution of chromosomes.</p> Signup and view all the answers

Which of the following statements best describes microtubules?

<p>They participate in a variety of cell activities and are dynamic.</p> Signup and view all the answers

Which function is NOT associated with the cytoskeleton?

<p>Production of cellular energy.</p> Signup and view all the answers

What is the general function of motor proteins in relation to the cytoskeleton?

<p>They interact with cytoskeletal filaments to enable movement.</p> Signup and view all the answers

In which process does the cytoskeleton play a crucial role?

<p>Cytokinesis</p> Signup and view all the answers

How do microtubules influence intracellular transport?

<p>By acting as tracks along which organelles move.</p> Signup and view all the answers

What is a distinguishing feature of intermediate filaments compared to microfilaments and microtubules?

<p>They primarily provide structural support and mechanical strength.</p> Signup and view all the answers

What characterizes the dynamic nature of cytoskeletal filaments?

<p>They can rapidly disassemble and reassemble as needed.</p> Signup and view all the answers

Study Notes

The Cytoskeleton: Movers and Shapers

  • The cytoskeleton is a network of fibers throughout the cytoplasm.
  • It organizes cell structures and activities, anchoring organelles.
  • It consists of three types of molecular structures: microtubules, microfilaments, and intermediate filaments.

Roles of the Cytoskeleton

  • Supports the cell and maintains its shape.
  • Interacts with motor proteins for cell motility.
  • Facilitates intracellular vesicle transport along "monorails".
  • Essential for cell division.
  • Likely regulates biochemical activities.

Microtubules

  • Hollow tubes with a wall made of 13 protofilaments.

  • Diameter: outer 25 nm, inner 15 nm.

  • Composed of α and β tubulin heterodimers.

  • Exhibit polarity (+ and - ends).

  • Involved in a wide variety of cellular activities, primarily involving motion driven by protein motors using ATP.

  • Crucial for determining organelle placement and intracellular transport.

  • Essential for chromosome migration during mitosis and meiosis, forming spindle fibers.

  • Microtubules are dynamic and adaptable, growing and shrinking independently based on GTP hydrolysis.

  • Microtubules are stabilized and organized by microtubule-associated proteins (MAPs).

Microfilaments

  • Two intertwined chains of F-actin (filamentous actin), made of G-actin monomers.
  • Diameter: 7 nm.
  • Exhibits polarity (+ and - ends).
  • Functions include muscle contraction, cytoplasmic streaming, cell locomotion, and cytokinesis. 
  • Support the cell and maintain its shape .
  • Form contractile rings during cytokinesis in animal cells.
  • Provide mechanical strength, connecting to the plasma membrane and cytoplasmic proteins.
  • Cytoplasmic streaming.
  • Generate locomotion (in cells like white blood cells and amoeba).
  • Interact with myosin to generate the force of muscular contraction.
  • Made of G-actin monomers that polymerize into F-actin filaments.
  • Have ATP or ADP binding sites.
  • Assemble head-to-tail.
  • Form a 3-D network inside the plasma membrane.
  • Exhibit dynamic instability.
  • Regulated by actin-binding proteins (ABPs).

Intermediate Filaments

  • Diameter: 8-12 nm.
  • Exhibit no polarity. 
  • Consist of several protein types (e.g., keratins, vimentins, neurofilaments, lamins).
  • Provide mechanical strength and resistance to shear stress.
  • Important structural components in epithelial cells, hair, nails, nuclear lamins, and neurofilaments of nerve axons.
  • Vimentins reinforce muscle and other cells.
  • Different IF types fulfil varied functions in various cell types.

Cytoskeletal Filaments' Clinical Significance

  • Mutations in cytoskeletal protein genes can lead to various diseases (e.g., ciliopathies, myopathies, cancers).
  • Drugs affecting microtubules (e.g., taxol, colchicine) or microfilaments (e.g., phalloidin) have biomedical research and therapeutic applications.

Clinical Applications

  • Drugs that inhibit microfilaments are used in biomedical research.
  • Drugs that inhibit microtubules are used in therapies for diseases like cancer.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

PM132 Cytoskeleton and movement DG 2024 PDF

Description

This quiz covers key concepts related to the cytoskeleton, including its structure, functions, and components such as microtubules and motor proteins. Test your understanding of how the cytoskeleton supports cell integrity and facilitates cellular processes. Ideal for students studying cell biology.

More Like This

Microtubules: Structure and Functions
24 questions

Microtubules: Structure and Functions

InnocuousGrace avatar
InnocuousGrace
Cytoskeleton Structure: Microtubules
16 questions

Cytoskeleton Structure: Microtubules

AdvantageousBodhran avatar
AdvantageousBodhran
Cell Movement and Cytoskeleton Structure
18 questions

Cell Movement and Cytoskeleton Structure

PoignantAllusion avatar
PoignantAllusion
Cytoskeleton and Its Functions
28 questions

Cytoskeleton and Its Functions

DazzlingOnyx5377 avatar
DazzlingOnyx5377
Use Quizgecko on...
Browser
Open
Browser
Browser