The cytoskeleton is a flexible internal framework that helps cells maintain shape, organize their contents, and respond to changing demands. This lesson introduces its basic organization, broad functions, and the history of how scientists came to understand it.
The cytoskeleton is a network of protein filaments in the cytoplasm of cells. It occurs in eukaryotes as well as in bacteria and archaea. In eukaryotic cells, the network can extend from near the nucleus toward the cell membrane. Its filaments are not permanent scaffolds: they can assemble, grow, reorganize, or disassemble as cellular needs change.
All flashcards
What does the cytoskeleton do?
It helps cells maintain shape, organize their contents, move materials, generate force, and carry out division and signaling.
What distinguishes intermediate filaments from microtubules?
Intermediate filaments are relatively stable and help cells resist tension; microtubules are dynamic tubulin-based tracks and structural components.
What is the role of septins in eukaryotic cells?
Septin complexes can form filaments and rings, provide attachment sites, and act as barriers to molecular diffusion.
How do focal adhesions participate in mechanotransduction?
They connect the cytoskeleton to the extracellular matrix, allowing mechanical forces to initiate cellular signaling.
How does FtsZ contribute to bacterial cell division?
FtsZ forms a division-site structure that helps recruit proteins involved in building new cell wall between daughter cells.
Quiz questions
Which arrangement is typical of many motile eukaryotic cilia and flagella?Answer: Nine outer microtubule doublets surround two central microtubules.
What is a key role of FtsZ in many bacteria?Answer: It helps organize the division site and recruit cell-wall-building proteins.
Which small GTP-binding protein is associated with lamellipodia formation?Answer: Rac
What does mechanotransduction describe?Answer: The conversion of mechanical forces into biochemical signals and cellular responses.
How does increased calcium enable muscle contraction?Answer: Calcium binds troponin, changing regulation so myosin can interact with actin.
Based on the Wikipedia article Cytoskeleton, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.