what is the difference between microtubles, microfilaments, and intermediate filaments?
Determine if the each of the following is true of microtubules, microfilaments, or intermediate filaments. Use the key below to indicate your answers.
MT = Microtubules; MF = Microfilaments; IF = Intermediate filaments
______ Straight, hollow tubes
______ Made of tubulin
______ Involved in cell transport
______ Provides tracts for organelle movement
______ Make up spindle fibers, centrioles, cilia, and flagella
______ Solid rods
______ Made of actin
______ Involved in muscle contraction and localized cell contractions
______ Form 3-D support network just inside the cell membrane
______ Form contractile ring that pinches dividing animal cell in two
______ Produces cytoplasmic streaming
______ Intermediate in diameter
______ Composition varies
______ More permanent
______ Reinforces cell shape and may fix organelle position
I see that you have several items to be answered. It would be better if we try to define each terms and from there you will be able to provide the answer in the blanks.
Microtubules are a component of the cytoskeleton made of globular proteins called tubulin, combined together to form a straight hollow tubes. It produces spindle fiber during cell division which eventually helps in contraction of the cell forming and cleavage.
Microfilaments are also called actin (a protein) filaments. There are thin filament found in cytoskeleton which primarily aid in transport. It has a tough structure that and allows cell motility or movements which includes muscle contractions. Microfilaments also produces cytoplasmic streaming due to actin.
Intermediate filaments are in the form of rods which are composed of varieties of alpha-helical segmanets such as 1A, 1B, 2A and 2B. They reinforces and support cell shape and may fix organelle position therefore more permanent than the rest.
Intermediate filaments 6-12 nm
micro filaments - >6nm
microtubules - 25nm
hope this helps :)