L5 Regulations of animal cell shape

What are the three major components of the cytoskeleton?

Microfilaments, intermediate filaments, and microtubules.

How do microfilaments differ in structure and function?

Thin strands like aho, composed of actin; they provide structural support and enable cell movement. Resists tension.

What are the three major components of the cytoskeleton?

Microfilaments, intermediate filaments, and microtubules.

How do microfilaments differ in structure and function?

Thin strands like aho, composed of actin; they provide structural support and enable cell movement. Resists tension.

How do intermediate filaments differ in structure and function?

If microfilaments is aho, this is miro. Composed of keratin coiled together. Super strong and tightly coiled. Maintains cell shape and anchors organelles.

How do microtubules differ in structure and function?

Microtubules are hollow tubes composed of tubulin; they resist compression, movement and organelle movement (walking motor proteins), and maintaining cell shape.

What is the role of the cytoskeleton in regulating cell shape?

The cytoskeleton maintains structural integrity and allows for changes in shape necessary for cell movement and division.

What are the three main types of cell junctions?

Tight junctions, desmosome junctions, and gap junctions.

How do tight junctions differ in structure and function?

Like the “water seal” of the junctions. Prevents movement of fluids across cells layers. Not good at forcing cells to stay together.

How do desmosome junctions differ in structure and function?

Like the “zip” of the junctions. Adhere cells together through intermediate filaments. Prevent cells from being pulled apart.

How do gap junctions differ in structure and function?

Like the “tunnel” of the junctions. Allow ions and small molecules to pass between cells. Allows rapid intercellular comms.

What is the ECM made of?

The ECM is composed of material secreted by the cell. eg, proteins, glycoproteins (like collagen), and polysaccharides.

Proteoglycan

Proteins with A LOT of sugar. They trap water; water resists compression; and therefore helps retain tissue shape.

Fibronectins & Integrins

1st. (the dinosaur looking thing) attach cells to ECM

2nd. (membrane proteins) attach ECM to cytoskeleton

Together they provide a communication link between the cell interior and the ECM.