Transport Electrophysiology

Def: flux

movement of mass substances across a membrane
What substances can freely diffuse across a membrane?
- Gases
- Hydrophobic
- Small polar
What substances can cross a membrane via facilitated diffusion?

A substance moving DOWN its concentration gradient
Def: active transport (primary)
- Movement of a substance against its concentration gradient.
- Energy required in the form of ATP.
Def: active transport (secondary)

Movement of one substance against its gradient, coupled with movement of another substance down its gradient.
Def: electrochemical potential
- Symbolized by (C)
- A difference in either electric potential or concentration of a substance across a membrane.
What is flux rate dependent on?

Determined by electrochemical potential (deltaC) and Membrane potential (P)
(P) is a function of what?

Molecular size and membrane partition coefficient, i.e., membrane solubility
What is the partition coefficient (beta)?

the ratio of the [ ] of the substance in the membrane, to [ ] in the aqueous solution in contact with the membrane.
When the C(outside) = C(inside), the partition coefficient (beta) = what?

Beta = 1

Author

Anonymous

100997

Card Set

Transport Electrophysiology

Description

MSS

Updated

2011-09-11T05:57:39Z

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