Daily Newsletter February 2, 2012
Today's Topic: The Cytoskeleton
The cell is not just a fluid filled sack, but an organized structure complete with internal supports. Consider it a highrise building that is just squishy. Creating the structure are a protein fibers (structural proteins). Structural proteins typically are in quatrenary structures, meaning that individual proteins combine to create the overall structure. The cytoskeleton is composed of Microtubules, Microfilaments, and a group of proteins referred to as the Intermediate Filaments.
The microtubules are one of the most well studied cytoskeletal elements. They are composed of the protein tublin, and are responsible for the flagella, mitotic spindles, internal structure, and movement of materials and vesicles within the cell (they act as roads on which vesicles are carried).
Microfilaments are composed of actin. They help to form structure, and are used in movement, such as mucle contraction, the formation of pseudopods and bulk transport.
The intermediate filaments are a family of structural proteins that are smaller than microtubules, but larger than microfilaments. There are a number of different types, and some are specific for a given cell type. Wikiepdia provides a good list of the different types of intermediate filaments in the article itermediate filaments.
Spectrin is a structural protien that was originally classified as an intermediate filament. In recent years, the importance of this protein to the cell membrane has become more noted, so it deserves it's own place. The structure of spectrin has it reclassifed as related to actin (microfilaments).
Daily Challenge: Cytoskeleton
Today, you are to describe in brief the function of the cytoskeletal elements listed above. You do not need to go in depth about the structure, at present the function is more important. Pick one of the above cytoskeletal elements to be your focus today. Write more about that element, including it's structure.
No comments:
Post a Comment