cytoskeleton

intermediate filaments

While microtubules may be disassembled and reassembled elsewhere, ________ _______ are often more permanent fixtures in the cell.

cytoskeleton

A network of protein fibers in the cytoplasm of a eukaryotic cell; includes microfilaments, intermediate filaments, and microtubules.

centriole

A structure in an animal cell composed of cylinders of microtubule triplets arranged in a 9 plus 0 pattern. An animal usually has a centrosome with a pair of these cylinders involved in cell division.

intermediate filaments

An intermediate-sized protein fiber that is one of the three main kinds of fibers making up the cytoskeleton of eukaryotic cells. These are ropelike, made of fibrous proteins

cytoskeleton structural, movement

As you saw in the chapter introduction, networks of protein fibers extend throughout the cell. Collectively called the _______, these fibers play a major role in organizing the structures and activities of the cell. And like a skeleton, they provide for ________ support as well as ________, including both the internal movement of cell parts and the swimming or crawling motility of some cells.

actin, thicker, myosin localized

Microfilaments are also involved in cell movements. _______ filaments and _________ filaments made of a type of motor protein called ________ interact to cause contraction of muscle cells. _________ contractions brought about by the actin and myosin are involved in the amoeboid (crawling) movement of the protist Amoeba and some of your white blood cells.

cilia, flagella

Microtubules shape and support the cell, and also guide the movement of chromosomes when cells divide, and they are the main components of ______ and _____.

intermediate filament

The outer layer of your skin consists of dead skin cells packed full of ________ ________.

microtubule

The thickest of the three main kinds of fibers making up the cytoskeleton of a eukaryotic cell; straight, hollow tube made of globular proteins called tubulins. These form the basis of the structure and movement of cilia and flagella.

microfilaments

The thinnest of the three main kinds of protein fibers making up the cytoskeleton of a eurkarytic cell; a solid, helical rod composed of the globular protein actin.

microtubules, microfilaments, intermediate

Three main kinds of fibers make up the cytoskeleton: __________, the thickest fiber; ________, the thinnest; and _________ filaments, in between in thickness.

microfilaments microfilaments

_______, also called actin filaments, are solid rods composed mainly of globular proteins called actin, arranged in a twisted double chain. ______________ form a three-dimensional network just inside the plasma membrane that helps support the cell's shape. This is especially important for animal cells, whick lack cell walls.

intermediate filaments proteins intermediate filaments

________ ______ are found in the cells of most animals. They are made of various fibrous ________ that supercoil into cables. _________ ________ reinforce cell shape and anchor some organelles

microtubules, tubulins tubulin subunits centrosome centrosomes

_________ are straight, hollow tubes composed of globular proteins called __________. Microtubules elongate by the addition of ________ proteins. They are readily disassembled, and their _______ can be reused elsewhere in the cell. In an animal cell, microtubules grow out from a region near the nucleus called the ________, which contains a pair of centrioles, each composed of a ring of microtubules. Plant cells lack ______ with centrioles and organize microtubules by other means.