Please enable JavaScript.
Coggle requires JavaScript to display documents.
Membrane Structure and Functions - Coggle Diagram
Membrane Structure and Functions
Cellular Membranes and Fluid Mosaics
cellular membrane
Lipids
Phospholipids
phospholipid bilayer
Amphipathic
both hydrophilic and hydrophobic regions
Glycolipids
Fluidity of membranes
Fluid
Unsaturated hydrocarbon
Viscous
Saturated hydrocarbon
Cholesterol
reduces membrane fluidity
fluidity buffer
fluid mosaic model
membrane is a mosaic of protein molecules bobbing in a fluid bilayer of phospholipids
Proteins
Types of proteins
Transmembrane proteins
goes through both halves of the membrane
Peripheral Proteins
loosely bound to the surface of the membrane
Integral proteins
go through one half of the membrane
Functions
Transport
Enzymatic activity
Signal transduction
Intercellular joining
Cell-cell recognition
Attachment to the cytoskeleton and extracellular matrix
Glycoproteins
Membranes in Selective Permeability
selective permeability
allows some substances to cross more easily than others
Transport proteins
Channel proteins
Aquaporins
Facilitates osmosis
Allows certain substances to cross the membrane
Carrier proteins
Passive Transport
Diffusion
Movement of particles of any substance so that they spread out into available space
Facilitated diffusion
temperature affects rate
Concentration gradient
density increases or decreases
No energy needed
Osmosis
Isotonic
same movement of the cell in and out
Hypertonic
more water out of the cell
Hypotonic
More water is going into the cell
osmoregulation
control of solute concentrations and water
Tonicity
gaining or losing water
ion channels
gated channels
Active Transport
Bulk Transport
exocytosis
fusion of vesicles with the plasma membrane
endocytosis
forms new vesicles
requires work
electrochemical
determines the net directions of ionic diffusion
concentration gradient
electrical gradient