Cell Membrane Outside of cell Inside (cytoplasm) Carbohydrate chains Proteins Protein channel Lipid bilayer Carbohydrate chains
TAKS Objective 2 – The student will demonstrate an understanding of living systems and the environment.
TEKS Science Concepts 4 -The student knows that cells are the basic structures of all living things and have specialized parts that perform specific functions, and that viruses are different from cells and have different properties and functions. The student is expected t (B) investigate and identify cellular processes including homeostasis, permeability, energy production, transportation of molecules, disposal of wastes, function of cellular parts, and synthesis of new molecules
Engage
Explore Semi-Permeability Lab Eggactly What I Predicted Cell Membrane Manipulative
Membrane structure Semi-Permeable Selectively Permeable Amphipathic~ hydrophobic & hydrophilic regions Fluid Mosaic Model
The Structure of the Cell Membrane Outside of cell Inside (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains
Membrane structure Phospholipids~ membrane fluidity Cholesterol~ membrane stabilization and fluidity “Mosaic” Structure~ Integral proteins~ transmembrane proteins Peripheral proteins~ surface of membrane proteins Membrane carbohydrates ~ cell to cell recognition;
Video 1
Random movement results in Solution – mixture of solute and solvent Solute – substance being dissolved Solvent – substance dissolving solute Living Things (Universal Solvent)-Water
Membrane traffic Passive transport~ diffusion of a substance across a biological membrane (NO ENERGY) [] = concentration Diffusion~ the overall movement of particles from a region of high [] to an area of low [] Osmosis~ the diffusion of water across a selectively permeable membrane
Results of Diffusion Dynamic equilibrium Homeostasis Once diffusion has evenly distributed the solute throughout the solvent; movement of particles continues with no change in [] Homeostasis Preservation of equilibrium
Diffusion depends on [] gradient [] gradient: the difference in [] of a substance across space Diffusion is said to move down a [] gradient Diffusion continues until there is NO [] gradient Ex: O2 diffuses into oxygen depleted blood
Diffusion Small molecules like WATER, OXYGEN, AND CARBON DIOXIDE can move in and out freely. Large molecules like PROTEINS AND CARBOHYDRATES CANNOT Charged IONS CANNOT
Osmosis Video 2
Osmosis~ the diffusion of water across a selectively permeable membrane
Questions Osmosis is the diffusion of _______ across a cell membrane. Osmosis and Diffusion are both types of __________ transport. Passive transport does or does not require energy? Small molecules can not move across freely. T or F Large molecules can move freely. T or F
Three Different Types of Solutions Isotonic Solution Hypotonic Solution Hypertonic Solution
Isotonic Solution The solute outside the cell is equal in concentration to the solute in the cell. The cell retains its shape. water moves equally in both directions
Hypotonic Solutions Solution outside the blood cell contains a lower [] of solute than inside of the cell. Water will diffuse in. cell will lyse (burst). Animal cells - cytolysis. Plant cells do not burst- turgur pressure— grocers use this idea
Cells in a Hypotonic Solution
Hypertonic Solutions The solution outside the cell has a higher [] of solute than inside of the cell. Water will diffuse out of the cell, causing the cell to shrink or crenate Why should you not salt meat before cooking? CRENATION PLASMOLYSIS
Cells in a Hypertonic Solution
In what type of solution would these cells be found?
Water balance Summary Osmoregulation~ control of water balance Hypertonic~ higher concentration of solutes Hypotonic~ lower concentration of solutes Isotonic~ equal concentrations of solutes
Water balance Summary Osmoregulation~ control in cells with cell walls: Turgid (very firm) - Hypo Flaccid (limp) - Iso Plasmolysis~ Hyper plasma membrane pulls away from cell wall
Plasmolysis Turgidity
Other Ways to Transport Molecules Across the Plasma Membrane Selective Transport
Review Covered Passive Transport Osmosis Does it require energy? NO!!! Diffusion
Osmosis What is osmosis? WATER The movement of ___________ across the cell membrane. Is it the movement of any other substance? NO!!!! WATER
Diffusion Mixing of two substances by the random motion of molecules. Molecules move from a region of high concentration to an area of low concentration.
How do other molecules cross the cell membrane??? Selective Transport Facilitated Diffusion (Another Passive Transport) Active Transport Protein Pumps Endocytosis Exocytosis
Selective Transport There are two types of selective transport Facilitated Diffusion DOES NOT require the use of energy Active Transport DOES require the use of energy
Facilitated Diffusion Glucose molecules High Concentration Cell Membrane Low Concentration Protein channel
Facilitated Diffusion Does facilitated diffusion require the use of energy? NO!!!! It uses a [] gradient to transport molecules The molecules move from an area of high [] to an area of low [] Most SUGAR molecules pass across the cell membrane by this method of transport
Carrier Proteins Carry Molecules Across the Membrane Good Example - transport of Glucose into the Cell
Active Transport Does active transport require the use of energy? YES!!! It uses ATP Transports against the [] gradient. Low to High [] Sodium Potassium Pump, Endocytosis and Exocytosis
Active Transport Molecule to be carried Molecule being carried Energy
Active Transport: Sodium Potassium Pump Move Sodium out of the cell Move Potassium into the cell Uses energy (ATP) Causes the protein to change shape Move against a [] gradient
Sodium Potassium Pump
Bulk Transport-Active Endocytosis Pinocytosis Phagocytosis Exocytosis
Endocytosis During ENDOCYTOSIS the Cell Membrane folds into a POUCH (Vescicle) that Encloses the Particles.
Two Types of Endocytosis: Pinocytosis and Phagocytosis PINOCYTOSIS ---"CELL DRINKING“—Small Particles PHAGOCYTOSIS---- "CELL EATING“-Large Particles
Treatments
Exocytosis EXOCYTOSIS is the opposite OR reverse of ENDOCYTOSIS. EXOCYTOSIS, wastes and cell products leave the cell.
Specialized Transport Summary Transport proteins Facilitated diffusion~ passage of molecules and ions with transport proteins across a membrane down the [] gradient Active transport~ movement of a substance against its [] gradient with the help of cellular energy
Elaborate Cell Membrane Bubbles Cellular Transport Flow Chart