Download Structure and Function of Cells

M. Tweedie
Room 54
Cytoskeleton
 The cytoskeleton is a network of protein filaments that
help:
 the cell retain its shape
 with cellular movement
 What are they?
 Microfilaments
 Microtubles
Microfilaments
 Made of Actin (same protein found in muscle)
 Maintain cell shape
 Aide in movement
 Move the Pseudopod (false foot):
projections of the
cell membrane of
eukaryotes

Microtubles
 Important in cell division (spindle fibers)
 They attach to and move chromosomes during cell
division
 In animal cells the Centrioles are centers for spindle
fiber organization
Cilia and Flagella
 Move the Cell
 Cilia – tiny hair-like projections that beat in rhythm
 Flagella – whip-like projections
 Cilia can also be used:
 To move substances along surface (lining of lungs)
 As sensory receptors (touch, sound, etc.)
Nuclear Envelope
 Double membrane that surrounds the nucleus
 Has pores that only allow certain substances to pas
through (NOT DNA!)
Cell Wall
 Plants have a cell wall surrounding their cell
membranes
 Made of Cellulose (polysaccharide)
 Gives structure and support
 Works with central vacuole to hold plant upright
(pressure inside)
Turgor Pressure in Plants!