Cytoskeleton & MovementDo Now:

1. Turn in Homework, get out notes from Friday (cytoskeleton)

2. Cell City analogies: If you havent done so, add ribosomes to the ER row, because it

should be Endoplasmic reticulum + ribosomes.

Finish any anaolgies you haven’t completed yet.

Cell City Presentations

• Your project should include:– Analogy reasoning for each part– A representation of each part that makes

sense

• Due Monday: 1 week. Don’t waste time!

Cytoskeleton

Cytoskeleton• Just like your body has a skeleton to

maintain its shape and size, cells have a cytoskeleton to do the same thing.

• Microfilaments are the smallest strands of the cytoskeleton

• Microfilaments are a polymer of a protein called actin.

• They’re used for cell movement and muscle contraction

• Microtubules are larger strands and are thicker and stronger.

• Microtubules are hollow tubes made of a protein called tubulin.

• During cell division, spindle fibers move chromosomes apart. Spindle fibers are microtubules.

Movement

• Some cells move using organelles called cilia and flagella

• Cilia are small hair-like structures on the outside of a cell.

• If a cell has cilia, it always has a lot of them!

• Cilia (and flagella) are made of microtubules bundled together.

• Flagella are much bigger than cilia, and cells that have them only have a few.

One More Way to Move: Pseudopodia

• Means “false foot”

• Think blob

How do cells move?

• Cilia: many tiny beating “hairs.”

• Flagella: a few long, whip-like propellers.

• Pseudopodia: flow from 1 spot to another.

• Do The Dance….