Microtubules are the dominant components of cilia and flagella Cilia short hair

Microtubules are the dominant components of cilia and

This preview shows page 6 - 7 out of 11 pages.

Microtubules are the dominant components of cilia and flagellaCilia– short, hair-like projections that extend from the surface of the cell oAnchored to a basal bodyoCauses steady movement of fluid along the cell’s surface oCystic fibrosis; cilia in lungs produce more mucus than normal; inhibit normal functions of lungs Flagella – typically longer, usually move an entire cell (ex. Sperm) Ribosome – sites of protein synthesis; rRNA; consists of two subunits Endoplasmic Reticulum (ER)– is network of membranes in the form of flattened sacs or tubules; extends from nucleusoRough ER– extends from nucleus, outer surface studded with ribosomes, sites of protein synthesis;Produces secretory proteins, membrane proteins, organellar proteins Ex. Live – release glucose into blood stream; inactivate detoxifying lipid-soluble drugs or substances oSmooth ER– extends from Rough ER, does not have ribosomes; it synthesizes fatty acids and steroids Live, kidney and intestinal cells smooth ER allows free glucose to enter blood stream; muscle cells Ca2+trigger contraction are releasedGolgi Complex– proteins synthesized by rough ER are transported to other regions of the cell; the first step in the transport is through GC. Consists of 3 to 20 cisternae.oCisternae– small, flattened membranous sacs with bulging edges that resemble a stack of pita bread 1.Proteins synthesized by ribosomes on the rough ER are usually bounded by a piece of the ER membrane, which eventually buds from the membrane surface to form a transport vehicle 2.Transport vehicles move toward the entry face of the Golgi complex. 3.Fusion of several transport vesicles creates the entry face of the Golgi complex and release proteins into its lumen (space) 4.Proteins move from the entry face into one or more medial cisternae (sacs between entry and exit faces). Enzymes in the medial cisternae modify the proteins to form glycoproteins, glycolipids and lipoproteins. Transfer vesiclesthat bud from the edgeof the cisternae move specific enzymes back toward the entry face and move some partially modified proteins toward the exit face 5.The products of the medial cisternae move into the lumen of the exit face 6.Within the exit face cisterna, the products are further modified and are secreted and packaged Underline – three general destinations for proteins that leave the Golgi Complex7.Some of the processed proteins leave the exit face and are stored in secretory vesicles. These vesicles deliver the proteins to the plasma membrane, where they are discharged by exocytosis into the ECF. (Ex. Pancreatic cells release the hormone insulin this way) 8.Other processed proteins leave the exit face in membrane vesicles that deliver their contents to the plasma membrane for incorporation into the membrane. In doing so, the Golgi complex adds new segments of plasma membrane, as existing segments are lost and modifies the number and distribution of membrane molecules.
Background image
Image of page 7

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture