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Flashcards in Chapter 3.4 Deck (7)
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What is Tonicity?

the ability of a solution to affect fluid volume and pressure in a cell .

-depends on concentration and permeability of solute


What are transport proteins?

In the plasma membrane, transport proteins carry solutes from one side of the membrane to the other.

- Saturation: As the solute concentration rises, the rate of transport rises, but only to a point - Transport Maximum (Tm).

2 types of carrier mediated transport:
Facilitated diffusion and active transport


List the types of Membrane Carriers

Uniport - carries only one solute at a time

Symport - carries 2 or more solutes simultaneously in the same direction (contrasport)

Antiport -Carries 2 or more solutes in opposite directions ( counter-transport) . Sodium-potassium pump brings in K+ and removes Na+ from cell


What is Facilitated diffusion?

carrier mediated transport of solute though a membrane down its concentration gradient

-does not consume ATP
-solute attaches to binding site on carrier, carrier changes confirmation, then releases solute on other side of membrane.


What is Active transport?

carrier mediated transport of solute though a membrane up (against) its concentration gradient
-ATP energy consumed to change carrier
-Examples of uses: sodium-potassium pump keeps K+ concentration higher inside the cell
-bring amino acids into cell
-pump Ca2+ out of cell


How does a Sodium-Potassium Pump work?

each pump cycle consumes one ATP and exchanges three Na+ for two K+

keeps the K+ concentration higher and the Na+ concentration lower with in the cell than in ECF

necessary because Na+ and K+ constantly leak though membrane


What are the functions of Na+ K+ pump?

-Regulation of cell volume
-Secondary active transport
-heat production
-maintenance of a membrane potential in all cells