When molecules diffuse across a cell membrane, the direction of movement is into the cell or out of the cell is determined by what?
concentration
proteins
channels
carriers
What types of molecules are lipids completely impermeable to?
large polar molecules
ions
large nonpolar molecules
small polar molecules
all polar molecules
all nonpolar molecules
small nonpolar molecules
How do molecules in the previous question diffuse across the membrane?
active transport
facilitated diffusion
osmosis
simple diffusion
What are two ways that active transport is different than facilitated diffusion?
Active transport requires energy
Facilitated diffusion requires energy
Active transport moves against the concentration gradient. It moves from low concentration to high concentration
Active transport moves against the concentration gradient. It moves from high concentration to low concentration
What are the three types of proteins in active transport
channel proteins
uniporters
symporters
antiporters
transporters
The movement of water across a cell membrane is referred to as which of the following?
What are capillaries?
blood vessels
arteries
veins
barriers
Substances exit a capillary by slipping between the cells through pores or intercellular clefts intercellular holes extracellular matrix( intercellular clefts, intercellular holes, extracellular matrix ).
