Cellular Organization(Chapter 3)Lecture MaterialsforAmy Warenda Czura, Ph.D.Suffolk County Community CollegeEastern CampusPrimary Sources for figures and content:Marieb, E. N. Human Anatomy & Physiology 6th ed. San Francisco: Pearson BenjaminCummings, 2004.Martini, F. H. Fundamentals of Anatomy & Physiology 6th ed. San Francisco: PearsonBenjamin Cummings, 2004.Amy Warenda Czura, Ph.D.1SCCC BIO130 Chapter 3 Lecture SlidesCellular Organizationcell = smallest living unithuman: ~75 trillion cells~200 different types2µm - 1m (average 50µm)two categories:1. sex cells: sperm and oocyte (egg)2. somatic cells: everything else-different cells have different shapes-unique morphology is related to functionAmy Warenda Czura, Ph.D.2SCCC BIO130 Chapter 3 Lecture Slides-all cells surrounded by plasma membrane: separates cell from environment-plasma membrane “holds in” the cytoplasm-cytoplasm consists of cytosol (fluid) and organelles (structures)-body cells surrounded by interstitial fluid (fluid outside membrane)Common Characteristics of all Eukaryotic Cells:1. Plasma Membrane-mostly phospholipid bilayer: dynamicAmy Warenda Czura, Ph.D.3SCCC BIO130 Chapter 3 Lecture Slides-interface between cell and environment-Functions:-physical barrier to maintain homeostasis:separates intracellular fluid from extracellular fluid, different conditionsin each-regulates exchange with environment-provides sensitivity: cell communicationand signaling-provides structural support: attachment siteto hold tissues together-Components:a. phospholipids: self assemble into bilayerAmy Warenda Czura, Ph.D.4SCCC BIO130 Chapter 3 Lecture Slidesb. cholesterol: resist osmotic lysisc. carbohydrates: linked to other molecules as proteoglycans, glycoproteins, andglycolipids-carb part protrudes from extracellular side creating outer carb layer called glycocalyx-functions of glycocalyx:-lubrication & protection-anchoring & locomotion-binding specificity (acts as receptor)-self recognitionAmy Warenda Czura, Ph.D.5SCCC BIO130 Chapter 3 Lecture Slidesd. proteins:-1/2 mass of membrane-integral proteins: span width of membrane-peripheral proteins: adhere to inner or outer surface-functions of membrane proteins:-anchoring proteins: attachment-recognition proteins: self identification byimmune system-enzymes: catalyze rxns in cytosol or extracellular fluid-receptors: bind ligands for signaling, or import/exportAmy Warenda Czura, Ph.D.6SCCC BIO130 Chapter 3 Lecture Slides-carrier proteins: transport solutes in/out-channels: move ions & H2O in/outTransport Across Plasma Membrane(on handout)Amy Warenda Czura, Ph.D.7SCCC BIO130 Chapter 3 Lecture Slides------------++++++++----++++++ +++K+K+DiffusionAmy Warenda Czura, Ph.D.8SCCC BIO130 Chapter 3 Lecture SlidesFacilitated diffusionOsmosisAmy Warenda Czura, Ph.D.9SCCC BIO130 Chapter 3 Lecture Slideslysis crenationActive transporte.g. Sodium-Potassiumexchange pump3 Na+ out2 K+ in40% cell ATPAmy Warenda Czura, Ph.D.10SCCC BIO130 Chapter 3 Lecture SlidesReceptor-mediated endocytosisAmy Warenda Czura, Ph.D.11SCCC BIO130 Chapter 3 Lecture SlidesAmy Warenda Czura, Ph.D.12SCCC BIO130 Chapter 3 Lecture Slides-selective permeability of membrane allows different conc. of molecules in/outside cells-inside surface is negatively charged due to abundance of proteins-outside surface is positively charged due to cations in extracellular fluids-phospholipids hold charges apart creating a transmembrane potential: unequal chargedistribution-transmembrane potential is measured in volts-cell potentials range -0.01V to -0.1V(10-100mV)------------++++++++----++++++ +++Amy Warenda Czura, Ph.D.13SCCC BIO130 Chapter 3 Lecture Slides-surface area of membrane can be increased by microvilli (for absorption or secretion)-microvilli = “fingers” of cell membrane containing a web of microfilaments and cytoplasm, anchored to cytoskeleton2. Cytoplasm-material enclosed by plasma membrane-occupies space between plasma membrane and nuclear membraneAmy Warenda Czura, Ph.D.14SCCC BIO130 Chapter 3 Lecture Slides-components:a. cytosol: fluid-high K+, low Na+-colloid solution: proteins and enzymes-nutrient reserves: carbohydrates, lipids,amino acidsb. inclusions-type and number varies with cell-e.g. glycogen, melanin, steroids, etc.c. organelles-carry out cellular functions-each has separate function-some have membranes-some free in cytosolAmy Warenda Czura, Ph.D.15SCCC BIO130 Chapter 3 Lecture Slides3. CytoskeletonA. Microfilaments< 6nm diameter-composed of actin-usually at periphery of the cell-Functions: 1. attach membrane to cytoplasm 2. attach integral proteins to cytoskeleton 3. in muscle cells interact with myosin to produce movement-Internal framework-4 possible typesof filaments:Amy Warenda Czura, Ph.D.16SCCC BIO130 Chapter 3 Lecture SlidesB. Intermediate filamentsC. Thick filaments- 7-11nm diameter- type varies with cell (e.g. collagen, elastin, keratin)- Functions: 1. strengthen cell and maintain shape 2. stabilize position of organelles 3. stabilize the cell relative to other cells- 15nm diameter- composed of myosin- muscle cells only- Function: to interact with actin to produce movementAmy Warenda Czura, Ph.D.17SCCC BIO130 Chapter 3 Lecture Slides- 25nm diameter- composed of tubulin- originate from the centrosome- very dynamic- Functions: 1. forms the foundation of the cytoskeleton 2. allows the cell to change shape and assists in mobility 3. involved in transport: molecular motorstravel along micotubule “tracks” 4. makes up the spindle apparatus for nuclear division (mitosis) 5. is the structural part of some organelles(centrioles, cilia, flagella)D. MicrotubulesAmy Warenda Czura, Ph.D.18SCCC BIO130 Chapter 3 Lecture Slides4. Centrosome-located nearnucleus-consists of matrix& pairedcentrioles-functions as microtubule organizing center-responsible for assembling spindle apparatusduring mitosis5. Cilia and Flagella-hair like projections-contain a microtubule core with cytoplasm covered in plasma membrane-anchored in the cytosol by basal bodiesAmy Warenda Czura, Ph.D.19SCCC BIO130 Chapter 3 Lecture SlidesCilia: short, numerous,function to sweep substances over cell surfaceFlagella: long, singular,function to propel cell through environment6. Ribosomes-site of protein synthesis-2 subunits:composed of rRNA & proteinFree ribosomes: in cytoplasm, manufacture proteins for use in cytoplasmFixed ribosomes: attached to endoplasmic reticulum, manufacture proteins for