Download The Cytoskeleton… but first:

Cytoskeleton & Movement
Do Now: 11/11 (Week 12)
OBJECTIVES:
1. Describe and distinguish structures for cell
movement: cilia, flagella, and pseudopodia.
2. Describe and distinguish the structures of the
cytoskeleton: actin microfilaments, tubulin
microtubules, and centrioles/centrosome
TASK:
1. Pass forward week 11 Do Nows.
2. Construct a protein production flowchart
showing the cell parts and materials used.
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.
Centrioles Organize Cell’s Internal
Space
• The centrioles are the cell part from which the
microtubules of the cytoskeleton grow.
• The position of the centrioles determines the
location of the nucleus, cell shape, and the
location of flagella and cilia in Eukaryotic cells
that have these.
• NOT found in: prokaryotes, most plants, fungi.
– Eukaryotic cell types have a tubulin network
attached to different protein structures MTOC,
usually around the nucleus)
– Prokaryotes use different cytoskeletal proteins
Cell Part: Centrosome & Centrioles
• FUNCTION: The
centrioles (2 per
centrosome) are
responsible for
coordinating the
division of
chromosomes
during cell
division AND
organizing the
cytoskeleton.
• During cell division, spindle fibers
move chromosomes apart. Spindle
fibers are microtubules.
Centriole Structure: Interesting Biogeometry (9-triplet 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. (9 doublet + 2 single)
• 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….
Movement in Animals
• What body systems work together to make
you move?
• How is that similar to the cell systems we
just learned about?
Homework
• On Syllabus