137-2 A Closer Look at the Cell Your objective is to…Describe the main functions of eachcell structure
14Cell Wall Plants, bacteria (prokaryotes), fungi, algae (protists) Provides structure and protectionGas and water exchangePlants - made of polysaccharide cellulose
15Nucleus Controls cell processes Contains DNA deoxyribose nucleic acid codes for protein and other molecules
16Chromatin Chromosomes Nucleolus Nuclear Envelope DNA bound to protein chromatin condenses during cell divisionNucleolusmake ribosomesNuclear Envelope2 layers with pores that allow for the passage of material
41Animal vs. Plant Cells Figure 7-5 Plant and Animal Cells Plant Cell NuclearenvelopeRibosome(attached)(free)Smooth endoplasmicreticulumNucleusRough endoplasmic reticulumNucleolusGolgi apparatusMitochondrionCell wallCellMembraneChloroplastVacuolePlant Cell
42Figure 7-5 Plant and Animal Cells CentriolesNucleolusNucleusNuclearenvelopeRoughendoplasmicreticulumGolgi apparatusSmoothMitochondrionCellMembraneRibosome(free)(attached)Animal Cell
437-3 The Cell Membrane Objectives: Describe the structure of the cell membraneDescribe how substances move through the cell
44Cell Membrane Structure: Lipids, Proteins, Carbohydrates Lipid bilayerFunctions:Regulates entry and exit of materialsProtection and supportCarbohydrate chains act as identification cards
45Fluids ICF = Intracellular Fluid (inside cell/cytoplasm) ECF = Extracellular Fluid (outside cell)Always dissolved particles in both of these fluidsDissolved particles = solutesConcentration of solutes can varyHigh = more soluteLow = less solute
46Figure 7-15 The Structure of the Cell Membrane Outsideof cellInside(cytoplasm)CellmembraneProteinsProteinchannelLipid bilayerCarbohydratechains
47DiffusionMovement of materials from a high concentration to a lower concentration until equilibrium is reachedrequires no energy = passiveWhat materials diffuse across a cell membrane?
50PermeabilityAbility of membrane to allow substances to penetrate/pass throughLevels of permeability:Permeable- any solutes can pass throughSemi-permeable/Selectively Permeable- certain solutes are selected to pass throughImpermeable- nothing is able to pass throughAll cell membranes are selective = picky/choosyImpermeability is not an optioncell would die! Why???
51Osmosis Diffusion of water across a selectively permeable membrane Types of Solutionshypertonic - higher concentration of dissolved particles (solute)hypotonic - lower concentration of dissolved particles (solute)isotonic - identical concentration
52Osmosis occurs b/c the solute is unable to pass through the membrane Osmosis occurs b/c the solute is unable to pass through the membrane. Water can always pass through the membrane.
56Problems in Organisms (Maintaining Homeostasis) Plantsturgor pressurerigid vs. wiltingAntibiotic effects on bacteriaSingle Celled Organismscontractile vacuolehomeostasisAnimalscells bathed in isotonic fluids “blood”
57Facilitated Diffusion specific protein channels for specific substances that cannot diffuse on their ownglucose channel
63Phagocytosis Large particles taken into cell Extension of cytoplasm engulfs large particles outside cellPocket folds into cell with contents and breaks loose from cell membrane forming vacuole inside cell (in cytoplasm).
67Multicellular Organisms Cells are interdependent (like a team)Cell specialization- separate roles for each type of cell (ex. Blood cell, nerve cell, muscle cell)Cells are specialized to perform particular functions within organism
68Levels of Organization Individual cellstissuesorgansorgan systemsorganismTissue- group of similar cells that perform particular functionOrgan- groups of tissues working togetherOrgan Systems- group of organs working together to perform specific function (11 major systems in human body)
69Smooth muscle tissueStomachMuscle cellDigestive system