Membrane Transport Flashcards
Which system regulates cell volume, maintains intracellular pH and ionic composition?
membrane transport system
Which system extracts and concentrates metabolic fuels, building blocks and extrudes toxic substances
membrane transport systems
which system generates ionic gradients?
membrane transport systems
what type of diffusion is the unaided spontaeneous movement of solute molecules down their concentration gradient until the solute equilibriates across the phospholipid bilayer (equilibrium at maximum entropy)
passive diffusion
at what speed do water, ethanol, urea and glycerol diffuse under passive diffusion?
fairly quickly
how fast do large uncharged polar molecules such as glucose diffuse under passive diffusion?
quite slowly
what speed do ions such as K+ and Na+ diffuse under passive diffusion?
extremely slowly
what type of membrane transport occurs down a concentration gradient through integral proteins?
facilitated diffusion
what is the term for transport of two molecules in the same direction is called
symport or cotransport
e.g transport of D-glucose in red blood cells
what is the term for transport of two molecules in the opposite directions?
antiport or countertransport
e.g transport of anions by red blood cells
which type of membrane transport requires metabolic energy?
active transport
what type of transport is responsible for maintaining intracellular concentrations of K+ and Na+ at optimum levels via ATP hydrolysis, electron transport chain and light?
primary active transport
what type of transport is driven by ion gradients and membrane potentials acorss cell membranes?
secondary active transport
e.g sugar transport in the gut driven by Na+ gradients across the apical membrane
which type of membrane transport involves the enzymatic catalysis in which a sugar is phosphorylated as it is transported?
group translocation transport
