Cytoskeleton

Motor Proteins and Movement

• Dynein converts chemical energy in ATP into mechanical work, powering the movement of flagella and cilia.
• Myosin interacts with actin filaments, enabling movement such as cell crawling and cytokinesis.

Microtubules and Vesicle Transport

• Microtubules play a crucial role in vesicle transport, guiding vesicles to their destinations.
• The microtubule organizing center (MTOC) in animal cells is the centrosome.
• Centrioles within the centrosome function to organize microtubules.
• Microtubules are composed of the protein tubulin.

Microtubule Functions

• Microtubules provide structural support to organelles, helping to maintain their shape and position.
• They also play a vital role in the cytoskeleton, contributing to the overall shape and organization of the cell.

Cilia and Flagella

• Cilia are involved in movement, sensing, and signaling, and are powered by the protein dynein.
• Bacterial flagella are composed of the protein flagellin.
• Eukaryotic flagella move through the coordinated bending of microtubules, driven by the movement of dynein arms.

Intermediate Filaments

• Intermediate filaments are involved in maintaining the cell's shape by forming long bundles or dense networks just inside the plasma membrane.
• Their main function is to provide mechanical support and stability to the cell.

Cytoskeleton

• The cytoskeleton is a dynamic system, constantly assembling and disassembling to facilitate cellular processes.
• Its main function is to provide shape, support, and movement to the cell.
• Actin filaments are the smallest type of cytoskeletal element.
• Intermediate filaments are not directly involved in movement.
• The cytoskeleton plays a crucial role in intracellular anchoring, enabling the attachment of organelles and other cellular structures.