Cytoskeleton: Structure, Function, and Cell Motility in Biology

What is the primary function of the cytoskeleton?

Providing structural support, cell motility, and regulation.

What are the three main types of fibers in the cytoskeleton?

Microtubules, microfilaments, and intermediate filaments.

How do microtubules contribute to cell division?

They move chromosomes during cell division.

What protein composes microtubules?

Tubulin.

What is the diameter of microtubules?

About 25 microns.

What is the role of motor proteins in relation to the cytoskeleton?

They interact with the cytoskeleton to facilitate movement and transport within the cell.

What structural feature do cilia and flagella share?

Both have a core of microtubules arranged in a '9 + 2' pattern.

What is the function of dynein in cilia and flagella?

Dynein drives the bending of cilia and flagella by causing conformational changes.

What type of protein are microfilaments primarily composed of?

Actin.

How do microfilaments contribute to muscle contraction?

Myosin molecules walk along actin filaments, pulling them together and shortening the cell.

What is the role of intermediate filaments?

They maintain cell shape and anchor the nucleus and organelles.

What is the size range of intermediate filaments?

8 to 12 nanometers.

How do microfilaments assist in cytokinesis?

They form a contracting belt that divides the cytoplasm during cell division.

What is the significance of the centrosome in relation to microtubules?

It is the structure from which microtubules grow in many cells.

What is the function of the cytoskeleton in cell communication?

It connects integral proteins inside the cell to the extracellular matrix outside.

What is the dynamic nature of the cytoskeleton?

It can dismantle in one area and reassemble in another to change cell shape.

What is the role of motor proteins in vesicle transport?

They carry vesicles or organelles along tracks provided by the cytoskeleton.

What is the function of cilia in the respiratory system?

They sweep mucus carrying trapped debris from the lungs.

How do actin-myosin interactions contribute to cytoplasmic streaming?

They drive the circular flow of cytoplasm, speeding material distribution within the cell.

What are the characteristics of microfilaments?

They are solid rods designed to resist tension and form a three-dimensional network just inside the plasma membrane.

What is the role of the nuclear lamina?

It is formed by intermediate filaments and helps maintain the shape of the nucleus.