Presentation on theme: "Cell Structure and Function"— Presentation transcript:
1Cell Structure and Function 7.3 Movement across the cell membraneGoalsIdentify the main function of the membraneDescribe what happens during diffusionExplain the processes of osmosis, facilitated diffusion, and active transport
2The Cell Membrane Functions • Regulates what enters and leaves the cell• Protection• Support
3The Cell Membrane Structure • Bilipid layerflexiblestrong• Protein molecules• Carbohydrates attached to the proteins
4The Cell Membrane Structure Outsideof cellCellmembraneProteinsProteinchannelLipid bilayerCarbohydratechainsInsideof cell(cytoplasm)Chunk and chew
5OsmosisDiffusion movement from area of high concentration to area of low concentrationSelective permeabilitySome substances cannot cross biological membranesOsmosis is the diffusion of water through a selectively permeable membrane
6DiffusionMolecules tend to move from an area of high concentration to an area of lower concentrationEquilibrium has been reached when the concentration is the same throughout the solutionDiffusion causes many substances to move across a cell membrane but does not require the cell to expend energy.
11How Osmosis Works Hypotonic - Below Strength Cell membrane Higher Concentrationof WaterWater moleculesCellmembraneLower Concentrationof WaterSugar moleculesHypertonic - Above StrengthRed blood cells burst when placed in distilled water. Make a labeled diagram to illustrate why. Use the terms osmosis, diffusion and concentration gradient.
12Osmotic PressureCan cause problems when water moves into hypertonic cell spacesBursting the cell like a balloonMost cells are bathed in isotonic fluids like bloodSome cells actively pump out water that is forced in by osmosis
13Biology Warm Up: Organelle Review Make a sketch of a plant cell. Label two features that identify it as a plant cell and not an animal cell.Without using your notes, draw and label1. the organelle responsible for absorbing light energy and using it to convert carbon dioxide and water to high-energy sugars (photosynthesis).2. the organelle that is responsible for converting sugars into high energy molecules. This is the powerhouse of the cell.3. the organelle that stores the genetic information that controls cell activities. Include the name of the molecule that carries that genetic information.4. the organelle responsible for assembling strings amino acids into proteins.
14Observing Cell Parts and Processes We’ll be doing this lab on Thursday.Please write a completeProcedure with materials and diagrams.We will be doing both parts of the lab.You must have this lab procedure written up and ready to go in order to start the lab next class.
15Facilitated Diffusion Protein ChannelThough fast and specific, still diffusionRequires higher concentration on one side of the membrane than on the otherRequires no energyGlucosemoleculesHighConcentrationCellMembraneProteinchannelLowConcentration
16Active Transport Movement against the concentration difference Requires input of energyMolecule tobe carriedLowConcentrationCellMembraneHighConcentrationMoleculebeing carriedLowConcentrationCellMembraneHighConcentrationEnergyEnergy
17Active Transport Movement against the concentration difference Requires input of energyEndocytosis Taking materials in through infoldings or pockets that break loose from the membrane and form a vacuolePhagocytosis Engulfing large particles by endocytosisExocytosis Vacuole fuses with cell membrane to expel contents
18WarmUp Osmosis/Diffusion 1. Mr. Schafer adds a drop of red food coloring to a large beaker of water. What do you expect to happen to the drop over time. Explain in terms of relative concentration of food coloring in different parts of the beaker. What word describes this phenomenon?2. This week, you will be placing your egg into a cup of syrup. What do you think will happen? Explain in terms of relative concentration of water inside and outside of the egg. What word describes this phenomenon?3. You will then place your egg into a cup of pure water. What do you expect to happen? Explain in terms of relative concentration of water inside and outside of the egg.What quality of the membrane surrounding the egg makes possible the phenomenon described in questions 2 and 3?5. Why do red blood cells burst when placed in water?
19Diversity of Cellular Life Describe Cell Specialization•Identify The organization levels in multicellular organisms
20Unicellular Organisms Multicellular OrganismsCells of multicellular organism do not live on their ownCells are specialized to perform certain functionsBoth prokaryotesand eukaryotes•everywhere•Some unicellular organisms are colonial
21Levels of Organization CellsSpecialized cells such as nerve cells, muscle cells depend on other specialized cells to provide their needs (food, oxygen)
22Levels of Organization CellsSpecialized cells such as nerve cells, muscle cells depend on other specialized cells to provide their needs (food, oxygen)2. TissuesA group of similar cells that perform a particular funciton
23Levels of Organization Cells2. TissuesA group of similar cells that perform a particular funciton•muscle•epithelial (skin inside and out)•nervous•connective (bone, blood, cartilidge, lymph)
24Levels of Organization Cells2. Tissues•muscle•epithelial (skin inside and out)•nervous•connective (bone, blood, cartilage, lymph)3. Organ - several tissues working togetherEach muscle is more than just muscle tissue
25Levels of Organization Cells2. Tissues3. Organ - several tissues working togetherEach muscle is more than just muscle tissue4. Organ systemsOrgans that work together to perform a specific function
26Levels of Organization Cells2. Tissues3. Organ4. Organ systemOrgans that work together to perform a specific function
27Levels of Organization 4. Organ systemOrgans that work together to perform a specific functionMuscularSkeletalCirculatoryNervousWe will go through all 11 systems in unit 10
28Levels of Organization Cells 2. Tissues3. Organ Organ systemSmooth muscle tissueMuscle cellStomachDigestive system