What is the supportive structure of an animal cell
– Composed of microtubules, intermediate filaments, and microfilaments
What is the supportive structure of a plant cell
– Composed of microtubules and microfilaments
What is polymerization?
- Assembly of monomers to extend the length of the
filament - Monomers added to the + end
What is depolymerization?
- Disassemblyofthefilament
-Monomers removed from the +end
Three major cytoskeletal filaments?
- microtubule
- intermediate filament
- microfilament
two types of motor proteins move along microtubules
- kinesin: away from centrosome
- dynein: towards the centrosome
Eukaryotic flagella
– Consist of several microtubules
– Move the cell by undulating—they whip back + forth
– Are surrounded by the plasma membrane
cilia
– Closely related to eukaryotic flagella
– Short, hairlike projections
– Cells generally have just one or two flagella – Some cells have many cilia
what is actin filaments AKA microfilaments
– Formed by polymerization of individual actin molecules into long strands
– Two strands coil around each other
– Grouped together into long bundles or dense networks – Usually found just inside the Plasma membrane
what is cell crawling:
- caused by actin filaments growing in one direction, moving the cell
types of movement caused by actin-myosin interaction
- cell crawling
- cell division in animals
- cytoplasmic streaming in plants
intermediate filaments
– Are defined by size rather than composition
– Many types exist, each consisting of a different protein – Provide structural support for the cell
– Are not involved in movement
