Lecture 6 Membrane Transport Flashcards
What kind of molecules does diffusion transport?
small and/or hydrophobic molecules
what is a concentration gradient
Where things tend to move from a higher concentration to a lower concentration
What is passive transport
AKA facilitated diffusion, no cell energy expended and moves with the concentration gradient
What are channels in passive transport
open holes in the membrane for specific molecules
what are carrier proteins in passive transport
change shape as molecules move through them
what is active transport
uses energy to move molecules against the concentration gradient
What is an ATP pump
use energy from ATP to move molecules against the concentration gradient
What are beta-transporters
They arre driven by energy from concentration gradients
What are symporters
both of the molecules move in the same direction
what are antiporters
molecules move in the opposite direction of each other
what is a NA+/K+ pump
located in the plasma membrane. pumps 2 K+ in and 3 NA+ out
what are Ca2+ pumps
they are located in the plasma membrane and the sacroplasmic/endoplasmic reticulum. pump Ca2+ out of the cytosol
what is calmodulin
a protein that is activated by Ca2+. When active, it turns on Ca2+ pumps
Ionic conditions inside vs outside the cell
Outside- NaCl and Ca2+
Inside- K+ and X- (most proteins are negatively charged)
What is resting potential
resting K+ channels in plasma membrane allow K+ to flow out/with its concentration gradient until a positive charge builds up on the outside of the cell
resting channels are always open
