Chapter 6.5-7.1 Flashcards
Cytoskeleton
A network of fibers extending through cytoplasm
What are the cytoskeletons functions
- Plays major role in organizing the structures and activities of the cell 2. Give mechanical support to cell and maintain its shape 3. Manipulate the plasma membrane bending it to form vacuoles or vesicles
What 3 types of fibers make up the cytoskeleton?
Microtubules - thickest Microfilaments - thinnest Intermediate filaments - medium
Microtubules
Hollow tubes constructed from globular proteins called tubulins Maintenance of cell shape Cell motility Chromosome and organelle movements
Microfilaments
Two intertwined strands Make up core of microvilli Maintenance and changes of cell shape Muscle contraction Cytoplasmic streaming Cell motility Cell division
Intermediate filaments
Fiberous protein coiled into cables Only found in some animals including vertebrates Maintenance of cell shape *sturdy Anchorage of nucleus and other organelles Formation of nuclear lamina Nucleus cage Permanent framework of entire cell
Dimer
A molecule made up of 2 components
Centrosomes
A region located near nucleus where microtubules grow
Centrioles
A pair of nine sets of triplet microtubules staged in a ring located Within the centrosome
Flagella
Cellular extension that contains microtubules Longer and fewer on cell Motion is like a fish tail Can move cell
Cilia
Cellular extensions that contain microtubules Lots of them on a cell and smaller Movement like oars on boat Some Also have signal receiving antenna for the cell*
How are each flagellum and cilium structured?
A group of microtubules sheathed in an extension of plasma membrane 9 doublets of microtubules are arranged in a ring with 2 single microbes in its center (9+2 pattern) Nonmotile cilia have “9+0”
Basal body
Microtubules triplets in a “9+0” pattern Anchors cilia or flagellum in the cell
Dyneins
Large motor protien that are attached along each outer microtubule doublet Has two “feet” that “walk” along the microtubules using ATP for energy
Myosin
Protein used to cause contraction of muscle cells
Pseudopodia
“False foot”
Cellular extensions used to move cell
Cytoplasmic streaming
Circular flow of cytoplasm within cells
Cell wall
Extra cellular structure of plant cell Protects plant cell Maintains shape and Prevents excessive uptake of water
Middle lamella
Thin layer between primary cell walls rich in sticky polysaccharides called pectins which glues cells together
(ECM) extra cellular matrix
Animal cells lack walls but do have ECM. Which consists of glycoproteins and other carb containing molecules
Collagen
Most abundant glycoprotein in the ECM of most animal cells
Fibronectin
ECM glycoprotein. Binds to cell surface receptor called integrins
Integrins
Cell surface receptor proteins that are built into plasma membrane Transmit signals between ECM and cytoskeleton
Plasmodesmata
Channels that connect plant cells Unify plant into one living continuum Enabling water and small solutes to pass between cells
