Cell Membrane, Membrane Transport, and Membrane Potential 4 Flashcards
How of the body is water?
60% of body weight in kg
What percentage of the body’s weight in kg is in the extracellular fluid?
20%
-5% blood plasma
-15% interstitial fluid
What percentage of the body’s weight in kg is in the interstitial fluid?
40%
What is the osmolarity difference between the extracellular and intercellular space?
none
-the osmolarity is equal inside the cells and outside of the cells most of the time
300 Osm
What is active transport?
the movement of something across the cell membrane the requires the input of energy
What are the two types of active transport?
- active transport with membrane proteins
- bulk (vesicular) transport
What are active transporter?
transmembrane proteins that move ions and hydrophilic building blocks across the plasma membrane against the concentration gradient
What are active transporters classified by?
- number of substances being transported
- direction substances are being transported
- source of energy for transport
What are active transporters that only move one substance across the membrane?
uniporter
What are active transporters that move more than one substance in the same direction across the membrane?
symporter
What are active transporters that move more than one substance in opposite directions across the membrane?
antiporter
What is primary active transport?
when the energy needed to move the substance against the concentration gradient comes directly from the breakdown of ATP
What is secondary active transport?
when the energy needed to move substance against the concentration gradient comes from one substance moving down its gradient is used to move a second substance against its concentration gradient
What is an example of a primary active transporter?
ATPase pumps
(Na-K pump)
What are the functions of the Na-K pump?
-maintain Na and K concentration differences
-establish negative membrane potential
