Please enable JavaScript.
Coggle requires JavaScript to display documents.
Membrane Structure & Function - Coggle Diagram
Membrane Structure & Function
Structure of the Plasma Membrane
Fluid Mosaic Model,Flexible, dynamic membrane composed of lipids, proteins, carbohydrates
Phospholipid Bilayer
Amphipathic Having both hydrophilic and hydrophobic parts, EX Phospholipids
Hydrophilic heads face outward
Hydrophobic tails face inward
Proteins
Integral,transport, signaling
Transmembrane proteins,the membrane, penetrate the core
Peripheral,structure, enzymatic support
Found on surface
Functions of Proteins Think of Tile mosaic
Transport
Enzymatic activity
Signal transduction
Cell-cell recognition
Intercellular joining
Attachment to the cytoskeleton and extracellular
matrix
Cholesteral,Maintains fluidity
Fluidity by fatty acid saturation, temperature, cholesterol
Embedded in membrane
Unsaturated- Double bonds that double bonds, makes it so the cell membrane is a little spaced out
Steroid Lipids have same function but in plants
Carbohydrates,Cell-cell recognition
Glycolipids
Carb+Lipid
Glycoproteins
Carb+Protein
Transport Across Membranes
Selective Permeability,Only certain substances cross easily,Nonpolar small uncharged
Passive Transport, does not require ATP
Simple Diffusion,Nonpolar/small molecules move freely EX cologne
Facilitated Diffusion EX glucose, ions
Uses channel or carrier proteins to help polar/charged molecules
Follows concentration gradient (high → low)
Dynamic equilibrium
Active Transport,requires ATP
Moves materials against gradient (low → high) EX Sodium-potassium pump
Membrane potential
electrochemical gradient
A chemical force
An electrical force
Endocytosis,Vesicle brings material into cell
Phagocytosis:
Cell eating
Pinocytosis
Cell drinking
Receptor-Mediated Endocytosis
Specific molecule uptake via receptor proteins
Exocytosis,Vesicles release contents outside cell
Cotransport
Transport Proteins
Channel proteins/aquaporins ,hydrphilic channel used as tunnel
Carrier proteins,bind to molecues
Concentration Gradient,divides the high and low concentration (not always visible)
Ion channels,facilitate the transport of ions
Concentration Gradient
Basis for diffusion
Molecules move from high to low concentration unless energy is used
Water Balance in Cells
Osmosis,Water follows the higher concentration of solute, needs semi permeable membrane
Osmoregulation,control of solute concentration and water balance EX Saltwater fish cannot live in Freshwater
Tonicity the measurement of osmosis
Aquaporins,allows water
Types of Solutions
Animal Cells
Isotonic: No net water movement → Cell stays normal
Hypotonic: Water enters → Cell swells → Lysis (burst)
Hypertonic: Water exits → Cell shrinks → Crenated
Plant Cells
Isotonic: Balanced flow → Cell is flaccid
Hypotonic: Water enters → Vacuole swells → Turgid (healthy)
Hypertonic: Water exits → Membrane pulls away from wall → Plasmolysis