Cell Structure and Function

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Cell Structure and Function. What is the smallest unit of matter that can carry on all of the processes of life? Cell What is an organism with only one cell? Unicellular What is an organism with more than one cell? Multicellular All living things are made up of cells - PowerPoint PPT Presentation

Transcript of Cell Structure and Function

  • Cell Structure and FunctionWhat is the smallest unit of matter that can carry on all of the processes of life?CellWhat is an organism with only one cell?UnicellularWhat is an organism with more than one cell?MulticellularAll living things are made up of cellsWhat led to the discovery of cells?Microscopes

  • Discovery of the Cell1665 Robert Hooke discovered dead plant cells in a slice of cork using a very simple microscopeAnton van Leeuwenhoek discovered living organisms in 1673Matthias Schleiden discovered living plant cellsTheodor Schwann found animal cells

  • Cell Theory

    What is the cell theory?The observations that Hooke and Leeuwenhoek made 150 years earlier led to the theory that follows1. All living things are composed of one or more cells2. Cells are the basic units of structure and function in living things3. Cells come only from the existing cells

  • The CellWhat characteristics do all cells share?Cell membranes and contain DNAWhat is the difference between prokaryotes and eukaryotes?Pros lack a nucleus and euks contain a nucleusWhat is a nucleus?Organelle that directs most of the activities of the cell and contains the cells DNA

  • ProkaryotesHave genetic material that is not contained in a nucleusGenerally smaller and simpler than eukaryotes- not all the time thoughCarry out every activity other living things do as wellExamples- bacteria

  • EukaryotesGenerally larger and more complexMany are highly specialized, many structures within cellContain nucleus in which their genetic material is separated from the rest of cellDisplay great variety, may be displayed as unicellular organism or multicellular such as- protists, fungi, animals and plants

  • Sec 2- Eukaryotic Cell StructureOrganelles- specialized organs found within the cellCytoplasm contains the various organelles, cytosol is the gelatin like fluid, surrounds nucleusNucleus- contains nearly all the cells DNA and with it the coded instructions for making proteins and other important molecules

  • Parts of the NucleusNuclear envelope- membrane that surrounds nucleus, dotted with pores that allows materials to move in and outNuclear matrix maintains the shape of the nucleusChromatin are strands of DNA and proteinChromosomes- threadlike structures that contain genetic information that is passed on from generation to generationNucleolus is a small dense region that controls protein synthesis and is the site of ribosome synthesis

  • Eukaryotic CellMitochondria is where energy is transferred from organic compounds to ATPRibosomes is the site of protein synthesisEndoplasmic Reticulum or ER serves as an intracellular highway- where lipid components of cell membrane are assembled2 Types of ERSmooth ER and Rough ERRough ER is covered with ribosomes, where synthesis of proteins takes placeSmooth ER is not, collections of enzymes that perform specialized tasks

  • Eukaryotic CellGolgi Apparatus, appears as a stack of closely apposed membranes, is the processes, packages, and secretes substances. Also prepares proteins for exportLysosomes, filled with enzymes, are organelles that digest viruses, bacteria, and old organelles. Also break down lipids, carbs, and proteinsVacuoles- saclike structures that store materials- water, salts, proteins, carbsMitochondria- organelles that convert the chemical energy stored in food into compounds that the cell can useChloroplasts- organelles that convert sunlike energy into chemical energy- photosynthesis

  • CytoskeletonCytoskeleton is made up of protein strands that give the cell its shape and support, also aids in movement2 major components include microtubules and microfilamentsMicrotubules are larger and hollow, assist in the movement of chromosomes during cell divisionCentrioles- help organize cell divisionCilia are short, in large numbers and assist with movementFlagella are long, less numbers and assist with movementMicrofilaments are smaller and contribute to cell movement and the contraction of muscle cellsMade of protein-actin

  • Sec 3- Cell BoundariesCell membrane- controls what goes in and out of the cell, provides protection and supportMade up of lipid bilayer- gives membrane flexible structure that forms strong barrier A selectively permeable membrane allows certain substances in while not allowing other substancesCell walls- lie outside of cell membranes, provides support and protection for cellFound in plants, algae, fungi, and many prokaryotesMade from fibers of carbohydrates and proteinsCellulose makes up cell walls in plants

  • Diffusion through Cell BoundariesDiffusion is the movement of molecules from an area of higher concentration to an area of lower concentrationEquilibrium- concentration of solute is same throughoutNo energy neededOsmosis is the diffusion of water through a selectively permeable membrane

  • Effects of Osmosis on CellsIsotonic- concentration of solutes is same inside and outside the cellWater moving in and out of cellHypertonic- solution has higher solute concentration than the cellWater moving out of cellHypotonic- solution has a lower solute concentration than the cellWater moving into cell

  • Facilitated DiffusionCell membrane channels help move molecules across the membraneFast and specific- only happens if there is higher concentration on one side of membraneDoes not require energy

  • Active TransportTransportation of materials against concentration differenceRequires energyMolecules generally transported by transport proteinsEndocytosis and exocytosis- processes that carry larger molecules and clumps of materials across

  • Endocytosis and ExocytosisEndocytosis and ExocytosisEndo- taking material into the cell by means of infoldings, or pockets of the cell membranePhagocytosis- extensions of cytoplasm surrounds particle and cell engulfs itPinocytosis- tiny pockets form around liquidExo- membrane of vacuole surrounding the material fuses with the cell membrane, forcing contents out of cell

  • Sec 4- The Diversity of Cellular LifeCompare multicellular organisms to unicellular organisms?Cell specialization- cells throughout an organism can develop in different ways to perform different tasksExamples

  • Levels of OrganizationLevels include; individual cells, tissues, organs, and organ systemsTissue-group of similar cells that perform a particular functionExamplesOrgan- group of tissues that perform a particular functionExamplesOrgan system- group of organs that work together to perform a specific functionExamples

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