Membranes and transport Flashcards
What are the functions of a membrane
-Separate cells from the external medium to create a unique intracellular environment
-allow selective transport of substrates in and out of the cell
-Provide a location for specialized pathways and proceses (eg. energy conversion of mitochondria)
-Rapid changes in electrical potential across the membrans of neurons as basis of the nervous system
-Localization of receptors to facilitate response to physiological signals
-Mediate cell-cell recognition and interaction
What are the characteristics of membranes
Describe the formation of membranes
How are vesicles used for drug delivery?
Describe permeability in membranes
Describe membrane composition
-Membranes are primarily composed of lipids and proteins
-More active membranes have a higher ratio of protein to lipid
-Composition of membrane components can be dynamic, particular for prokaryotes
What is the relationship between temperature and lipids?
-Too high temp destroys lipids
-They function 10-20 degrees above transitional melting temperature
-Favours dynamicism
What type of bonds lower transitional melting temp?
-Increased cis-double bonds (unsaturated)
-More dynamic and flexible
Explain the fluid mosaic model of membrane structure
-Membranes are dynamic structures due to the nature of the non-covalent interactions
-Lipids and proteins freely diffuse in the plane of the membrane
-Lateral movement of proteins and lipids within the membrane is very rapid
-Movement across the membrane is restricted
Explain transbilayer movement
Describe membrane fluidity
What are lipid rafts?
What are membrane proteins and the 3 categories?
What are peripheral membrane proteins?
What are lipid-anchored membrane proteins?
What are integral membrane proteins?
Describe hydrogen bonding within membrane-spanning regions
What is the distribution of amino acids in integral membrane proteins?
What is simple diffusion?
What is facilitated diffusion? channels vs carriers
What is coupled transport?
What is active transport? primary vs secondary
What is P-Type ATPase?
What is V-Type ATPase?
What is ABC transport?
Explain secondary active transport of glucose uptake into intestinal epithelial cells
What are the functions of ion channels?
Describe the specificity of K+ channel
What regulates the speed of K+ channels?
