Cytoskeleton and Extracellular Matrix

These flashcards cover fundamental concepts related to the cytoskeleton and extracellular matrix as detailed in lecture notes.

What is the cytoskeleton composed of?

The cytoskeleton is built on a framework of three types of protein filaments: intermediate filaments, microtubules, and actin filaments.

What is the main function of intermediate filaments?

To enable cells to withstand the mechanical stress that occurs when cells are stretched.

What do keratin filaments provide in vertebrate epithelial cells?

Keratin filaments provide structural diversity across different types of epithelium in the vertebrate body.

What role do microtubules play in eukaryotic cells?

Microtubules create a system of tracks for the transport of vesicles, organelles, and other cell components.

How do motor proteins function in relation to microtubules?

Motor proteins actively transport organelles and macromolecules along microtubules.

What are actin filaments essential for?

Actin filaments are essential for many of the cell’s movements, especially those involving the cell surface.

What are the two main classes of extracellular macromolecules in the ECM?

Polysaccharides (glycosaminoglycans) and fibrous proteins (such as collagen and elastin).

What is the main structural role of collagen?

Collagen provides tensile strength and regulates cell adhesion in the extracellular matrix.

What is the role of fibronectin in the ECM?

Fibronectin links ECM to cells, allowing attachment through integrin receptors.

What function do glycosaminoglycans (GAGs) serve in the ECM?

GAGs resist compression and help provide hydrated space around cells.

What is the cytoskeleton composed of?

The cytoskeleton is built on a framework of three types of protein filaments: intermediate filaments, microtubules, and actin filaments.

What is the main function of intermediate filaments?

To enable cells to withstand the mechanical stress that occurs when cells are stretched.

What do keratin filaments provide in vertebrate epithelial cells?

Keratin filaments provide structural diversity across different types of epithelium in the vertebrate body.

What role do microtubules play in eukaryotic cells?

Microtubules create a system of tracks for the transport of vesicles, organelles, and other cell components.

How do motor proteins function in relation to microtubules?

Motor proteins actively transport organelles and macromolecules along microtubules.

What are actin filaments essential for?

Actin filaments are essential for many of the cell’s movements, especially those involving the cell surface.

What are the two main classes of extracellular macromolecules in the ECM?

Polysaccharides (glycosaminoglycans) and fibrous proteins (such as collagen and elastin).

What is the main structural role of collagen?

Collagen provides tensile strength and regulates cell adhesion in the extracellular matrix.

What is the role of fibronectin in the ECM?

Fibronectin links ECM to cells, allowing attachment through integrin receptors.

What function do glycosaminoglycans (GAGs) serve in the ECM?

GAGs resist compression and help provide hydrated space around cells.

What are the primary building blocks of microtubules?

Microtubules are composed of tubulin subunits, which are dimers of \alpha-tubulin and \beta-tubulin.

Which motor proteins are associated with microtubules and in which directions do they move?

Kinesins generally move toward the plus end of a microtubule (outward from the cell body), while dyneins move toward the minus end (inward toward the cell center).

What are integrins and what is their function?

Integrins are transmembrane receptor proteins that link the intracellular cytoskeleton to the extracellular matrix, facilitating cell signaling and mechanical attachment.

What motor protein family interacts with actin filaments to facilitate muscle contraction?

The myosin family of motor proteins utilizes ATP hydrolysis to move along actin filaments.

What is the basal lamina?

A thin, flexible, and tough sheet of extracellular matrix that underlies all epithelial cell sheets and surrounds individual muscle and fat cells.

How do desmosomes contribute to cell-to-cell adhesion?

Desmosomes are specialized junctions that link the intermediate filaments of adjacent cells together, providing great mechanical stability to tissues.

What is the specific function of gap junctions?

Gap junctions provide direct channels for the passage of ions and small water-soluble molecules between the cytoplasm of adjacent cells.