Download Microfilaments Intermediate Filaments Extracellular Matrix

Microfilaments,
Intermediate Filaments,
AND
Extracellular Matrix
By David Ryu
AP Biology
Who discovered Microfilaments?
• Paul Wintrebert discovered the cytoskeleton
in 1931.
• And microfilaments and intermediate
filaments are part of the cytoskeleton
Microfilaments
•
•
•
•
Polymers of actin(a globular protein)
Each rod is about 7 nanometers long
They are present in all eukaryotic cells
Exists in edges of cells
• A Globular Protein is a twisting amino acid
chain that increase protein’s solubility in
water.
Microfilament Function
•
•
•
•
Help make up the cytoskeleton
Bears tension in muscle contraction
Supports cell membrane and structure
Thousands of microfilaments exist parallel
with each other, “interdigitated” with myosin.
Microfilaments Diseases
• Muscular Dystrophy
-Inherited genetic disorder
-Actin can’t connect to plasma
membranes
• When muscles contract, the actin doesn’t bear
tension
• Weakens the plasma membrane
• Intermediate filaments
Cool Fact About Microfilaments
•Microfilaments have a
fast-growing end and
a slow-growing end,
and fast-growing end
is directed outward!
Intermediate Filaments
• Its diameter is 8-12 nanometers in length
• Also help make up the cytoskeleton along
with microfilaments and microtubules.
• There are 5 different types
• But always include Keratin, a fibrous
protein
Intermediate Function
• Reinforces the shape of the cell
• Maintains certain organelles in place
such as plasma membrane and nucleus
• Framework for the cytoskeleton
Facts on Intermediate Filaments!
•Even if a cell dies,
intermediate filament
networks will still live
on, maintaining the cell
structure!
Extracellular Matrix
• Cellulose: Plant Cells to Extracellular Matrix: Animal
Cells
1. Collagen-most abundant protein and forms
strong fibers
2. Fibronectin- protein that glues ECM to
Integrin
2. Integrin- surface receptor proteins built into
plasma membrane
Proteoglycans
• These glycoproteins are woven inside a
network of proteoglycans, or a proteoglycan
complex
-Proteoglycan is a protein core with many
sugar chains attached covalently
-Proteoglycan complex - a long
polysaccharide attached by hundreds of
proteoglycans attached noncovalently
Cool Facts on ECM
• The carbohydrate chains attached
to the protein cells in
proteoglycan keeps your skin
healthy and smooth.
• The less chains attached, the
more wrinkles in your skin will
get-aging!
Credits
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
http://www.google.com/imgres?q=microfilaments&hl=en&sa=X&biw=1440&bih=702&tbm=isch&p
rmd=imvns&tbnid=FI2UNChx19lhttp://www.wisegeek.com/what-are-globular-proteins.htm
http://www.ncbi.nlm.nih.gov/books/NBK21560/
http://www.biog1105-1106.org/demos/105/unit1/fibrous_v_glob.html
http://www.google.com/imgres?q=microfilaments&num=10&h
http://www.biology4kids.com/files/cell_microfilament.html
http://www.cytochemistry.net/cell-biology/intermediate_filaments.htm
http://www.daviddarling.info/encyclopedia/G/globprot.html
http://www.chemistryexplained.com/Ge-Hy/Globular-Protein.html#b
http://www.ncbi.nlm.nih.gov/books/NBK21560/
http://www.spainfitness.com/en/beauty-and-bodycare/articulo/proteoglycans.html
http://www.enerex.ca/en/articles/amino-sugars
http://classes.kumc.edu/som/cellbiology/cytoskeleton/microfilaments/tut8.html
http://en.wikipedia.org/wiki/Muscular_dystrophy
http://www.encyclopedia.com/topic/Cytoskeleton.aspx
http://www.ncbi.nlm.nih.gov/pubmed/15690074
AP Biology book
This concludes my presentation
• Any Questions?
• Thank you for watching!