loosely attached to either external or internal cell wall
Chemical concentration gradient
move from high concentration to low
electrochemical forces
seperation of charged ions across a membrane
anions attract cations
Passive membrane transport
no energy required
high concentration to low (diffusion)
Active Transport
Energy required
moved against concentration gradient
Simple diffusion
small or nonpolar molecules
osmosis
applies only to the movement of water
Isotonic Solutions
equal water concentration to inside cells
Hypertonic solutions
less water (more solute)> draws water out of cell
cell shrinks (crenates)
Hypotonic solutions
more water (less solute)> water moves into cell
cell bursts (lyses)
In a resting muscle cell the membrane potential (E) is approximately____ mV and the cell is termed "___."
-95mV, polarized
All resting cells have similar proportions of ions across their plasma membranes. knowing this, predict which ion will be found to have a greater plasma concentration than normal if hemolysis occurs as a blood sample is collected.
when a hormone stimulates a target cell, it binds receptors. This binding produces a second messenger inside the cell. The "first" messenger is________.
Facilitated Diffusion
large or polar molecules
requires specific integral protein that binds to molecule to be transported
Bulk Filtration
diffusion of both liquids and dissolved molecules through hydrostatic presssure
Active transport
May involve ion pumps
bulk transporty
Exocytosis
Out of the cell
endocytosis
into the cell
Phagocytosis
nonspecific uptake of particles by formation of membrane extensions (pseodopia) that surround particles to be engulfed
Pinocytosis
nonspecific uptake of extracellular fluid
receptor-mediated endocytosis
engulfing of specific molecules bound to receptors on the surface of the plasma membrane