Intermediate filaments help support the shape of the cell

Intermediate filaments help support the shape of the cell -...

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Intermediate filaments help support the shape of the cell. Microfilaments are made of the protein actin and are involved in cell motility. They are found  in almost every cell, but are predominant in muscle cells and in cells that move by changing  shape, such as phagocytes (white blood cells that scour the body for bacteria and other  foreign invaders). Flagella  and  cilia  protrude from the cell membrane and make wavelike movements.  Flagella and cilia are classified by their lengths and by their number per cell: Flagella are  long and few; cilia are short and many. A single flagellum propels sperm, while the  numerous cilia that line the respiratory tract sweep away debris. Structurally, both flagella  and cilia consist of microtubules arranged in a “9 + 2” array—that is, nine pairs (doublets) of  microtubules arranged in a circle surrounding a pair of microtubules (Figure 3). 
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Unformatted text preview: • Centrioles and basal bodies act as microtubule organizing centers (MTOCs). A pair of centrioles (enclosed in a centrosome) located outside the nuclear envelope gives rise to the microtubules that make up the spindle apparatus used during cell division. Basal bodies are at the base of each flagellum and cilium and appear to organize their development. Both centrioles and basal bodies are made up of nine triplets arranged in a circle (Figure 3). • Peroxisomes are organelles common in liver and kidney cells that break down potentially harmful substances. Some chemical reactions in the body produce a byproduct called hydrogen peroxide. Peroxisomes can convert hydrogen peroxide (a toxin made of H 2 O 2 ) to water and oxygen. Figure 2. The general organization of a typical cell....
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This note was uploaded on 11/10/2011 for the course PT 101 taught by Professor Staff during the Spring '10 term at Texas State.

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