Microtubules and microfilaments are components of the cytoskeleton in eukaryotic cells. Microfilaments are double helix in structure, flexible, strong and mainly composed of actin. Microtubules are helical-latticed, stiff and primarily composed of tubulin.
You'll have to come up with your own analogies. Writing a bunch of random analogies down on the internet isn't going to help your story at all. You have to have analogies that actually have something to do with your own characters, setting, and plot.