cell functions and regulation Flashcards
week 7
5 functions of cells
Uptake materials from the environment
Excrete waste products
Respond to changes in the environment
Excitable membrane potential
Selectively permeable cell membrane
how do channel proteins work?
weakly interact with solutes forming pores in the membrane which allows solutes to diffuse through
how do transporter proteins work?
specifically bind the solute and undergo a conformational change to release the solute on the other side of the membrane
define active transport
transport of solutes against their conc gradient eg. K+ into cells
define facilitated passive transport
example
use of channel or transporter proteins to transport solutes with low permeability down their concentration gradient eg. transport of glucose
define simple diffusion
transport of small nonpolar solutes down their conc gradient
channel proteins form … pores to admit cargos of specific size/ charge eg. small ions
aqueous
4 stages of transport through transporters
- solute binding
- conformational change
- solute release
- conformational rearrangement
what do transporters display?
saturation kinetics
define uniports
transport protein that facilitate the movement of a single type of molecule across a cellular membrane in one direction
define symports
transport protein that facilitate the movement of 2 types of molecules across a cellular membrane in the same direction
define antiports
transport protein that facilitate the movement of 2 types of molecules across a cellular membrane in opposite directions
define primary active transporters
moving solutes against their conc gradient using energy from ATP hydrolysis
what energy source do primary active transporters use to drive transport?
example
ATP hydrolysis
Na/ K ATPase
what do secondary active transporters use to drive transport?
example
the ion gradient set up by primary active transporters
Na dependent glucose transporter in the gut villi
