9.19 Membrane Properties - Carrier-Mediated Transport Flashcards
saturability is a diagnostic characteristic of __________ transport
carrier-mediated transport
why is there saturability? (2)
- finite number of transporters
2. each transporter has finite turnover
what are the two diagnostic characteristics of carrier-mediated transport?
- saturability
2. selectivity
for carrier-mediated transport, flux is dependent on ___________. What is the equation for flux?
Jmax
J = (Jmax*[S])/(Kd + [S])
Kt is the substrate concentration at which ________________
half of the transporters are occupied
occurs when two or more substrates of a particular structure attempt to simultanously occupy the transporters. There is an increase in the Kt.
competitive inhibition
in competitive inhibition for a transporter, Kd is ________ and Jmax ___________
increased (takes more of original to half saturate)
stays the same
cocaine is an example of ________________ for serotonin
competitive inhibition
there is no ATP required in __________ __________ (membrane protein)
facilitated
CAN’T generate net flux against gradient:
facilitated diffusion
__________ __________ requires an energy source.
active transport
Develops and maintains transmembrane solute gradients
active transporters
in primary active transport, the immediate energy source is _______. in secondary active transport the immediate energy source is _______________.
ATP
existing trans-membrane ion gradients
the most common ion whose gradient is tapped into is ______
Na+
the inside of a cell has _______ K+ and _____ Na+
high K+
low Na+
