Actin Polymerization and Filament Structure

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Which of the following is a function of the cytoskeleton?

DNA replication

Protein synthesis

Cellular respiration

Cell shape maintenance (correct)

What are the three types of protein filaments that make up the cytoskeleton?

Golgi apparatus, mitochondria, endoplasmic reticulum

Lysosomes, peroxisomes, vacuoles

Intermediate, microtubules, actin (correct)

Lipids, carbohydrates, nucleic acids

What is the main role of actin filaments in the cell?

Cell shape and movement (correct)

DNA replication

Cellular respiration

Protein synthesis

What is the process of actin filaments forming long chains called?

Polymerization Signup and view all the answers

Which component of the cytoskeleton determines cellular organization and polarity?

Actin filaments Signup and view all the answers

What are the main functions of the cytoskeleton?

Cell shape maintenance and cell movement Signup and view all the answers

Which protein is responsible for causing motion inside cells in association with parts of the cytoskeleton?

Myosin Signup and view all the answers

What is the function of actin-associated motor proteins?

Cargo transportation Signup and view all the answers

Which type of myosin is involved in muscle contraction in most animal cells?

Myosin II Signup and view all the answers

What is the role of actin filaments and myosin (II) during cytokinesis?

They form contractile structures Signup and view all the answers

Which motor protein has a tail that can bind to transporting vesicles?

Myosin I Signup and view all the answers

What is the main function of ATP in actin-dependent motor proteins?

Mechanical energy Signup and view all the answers

Which type of actin crosslinker forms more rigid bundles?

Filamin Signup and view all the answers

What happens when ATP is hydrolyzed to ADP in actin filaments?

Reduces strength of binding between monomers Signup and view all the answers

Which protein inhibits nucleation in actin polymerization?

Profilin Signup and view all the answers

What type of actin crosslinker forms 3D gel-like networks?

Filamin Signup and view all the answers

Which end of actin filaments is usually shorter than microtubules?

(-)-End Signup and view all the answers

Which process is NOT known to be essential for cell movement involving actin?

All of the above processes are essential for cell movement Signup and view all the answers

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

Directing intracellular transport Signup and view all the answers

What is the function of actin filaments in a cell?

Determining the shape of a cell and enabling cell locomotion Signup and view all the answers

Which type of cytoskeletal filament is made up of elongated and fibrous subunits?

Intermediate filaments Signup and view all the answers

What is the main function of microtubules in a cell?

Directing intracellular transport Signup and view all the answers

Which type of cytoskeletal filament is involved in maintaining mechanical integrity?

Actin filaments Signup and view all the answers

What is the function of adherens junctions in a cell?

Occurring at cell-cell junctions Signup and view all the answers

Which proteins interact with actin filaments to help move vesicles and organelles in the cell periphery?

Mitochondria Signup and view all the answers

What is the main function of the sarcomere in muscle cells?

To contract the muscle Signup and view all the answers

What molecular events are involved in muscle contraction?

Crossbridge cycling Signup and view all the answers

What is the role of tropomyosin and troponins in striated muscle?

To block the binding of myosin to actin Signup and view all the answers

What triggers the release of calcium ions in muscle contraction?

Depolarization of myofibrils Signup and view all the answers

Which drug can be used to stain actin filaments and block their depolymerization?

Phalloidin Signup and view all the answers