Cytoskeleton

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

• a) Microfilaments

• b) Microtubules

• c) Ribosomes

• d) Intermediate filaments

What is the primary function of microfilaments in the cytoskeleton?

• a) Providing structural support and rigidity to the cell

• b) Facilitating intracellular transport

• c) Facilitating cell division and cytokinesis

• d) Anchoring organelles within the cell

Which protein is a major component of microtubules in the cytoskeleton?

• a) Actin

• b) Myosin

• c) Tubulin

• d) Keratin

Actin filaments are strong, rigid structures

• True

• False

Treadmilling is associated with what?

• Growing tubulin filaments

• Growing actin filaments

• Growing myosin filaments

• Cytokinesis

A myofibril consists of what?

• Two types of filaments, actin and myosin

• chain of sarcomeres

• 2 Stacked Z discs

• Three types of filaments, actin, myosin and tubulin

Sarceomere lengthening is caused by the myosin filaments sliding past the thin actin filaments?

• True

• False

During muscle contraction what happens to the myosin and actin filaments?

• They both shorten

• The both lengthen

• Myosin gets longer, actin shorter

• They stay the same

What causes the movement of the tropomyosin complex?

• Ca binding to the troponin complex

• Na binding to the troponin complex

• Ca binding to the tropomyosin complex

• Na binding to the tropomyosin complex

Actin filament is best described as?

• A hollow cylinder of actin molecules

• A twisted chain to actin molecules

• Two globular heads and long tails intertwined

• A linear single chain