membrane transport Flashcards
the body is in a state of chemical
disequilibrium
phagocytosis only occurs in
certain white blood cells
type of passive transport
all diffusions and osmosis
the main routes for water movement into and out of the cell
water channels/aquaphors
ion channels when open allow ions to pass between ____ and ____
ECF and ICF
the body is always in osmotic equilibrium T/F
true
diffusion is more complicated in an open system compared to a cell membrane T/F
False
ECF contains
interstial fluid and blood plasma
how does secondary active transport work
uses energy in the concentration gradient of one molecule to push molecules against their concentration gradient
glucose transport into various types of cells can be accomplished via ___ or ____
Facilitated diffusion (glut) or secondary active transport (glucose form intestinal or kidney lumen)
diffusion directly across the phospholipid bilayer of the membrane is
simple diffusion
movement of the cytoskeleton and intracellular transport of the vesicles require
energy
ficks law says that diffusion rate ___ with an ____ in a surface are, concentration gradient, or membrane permeability
increases, increase
what happens when you have an area of high concentration or solid solute into a body of water and the molecules are allowed to naturally diffuse
equilibrium
to import large molecules cells use
phagocytosis and endocytosis
diffusion rate per surface area of the membrane is called
flux
total volume of water in the human body is ____ of body weight
60%
net movement of molecules occurs until concentration is
equal
how do large solutes like monosaccharides get across the membrane
by carriers
molecules still at equilibrium by one molecules exits and one enters is called
dynamic equilibrium
difference between carriers and channels
channels are open on one side and channels are continuous
what do swing gates determine
if the channel is open or closed
movement of substances across membranes can be classified by the ___ or by the ____ through a membrane protein
energy requirements and physical pathways
a carrier that moves more than one kind of molecules at one time
cotransporter
pressure that must be applied to oppose osmosis
osmotic pressure
most cells produce cell-surface receptors that specifically bind and internalize LDL by
receptor- mediated endocyotosis
materials leave the cell by
exocytosis
because water can move freely across cells and ECF, the ECF and ICF are in a state of
osmotic equilibrium
transmembrane proteins enclosing a hydrophilic pore
ion channels
diffusion concentration is
high to low concentration
how does primary active transport work
energy to push molecules against their gradient comes from ATP
active transport id divided into 2 types:
primary and secondary
active transport creates a state of
disequilibrium
glucose enters most of the cells via ____ with the help of various _____
facilitated diffusion, GLUT transporters
passive, transports down gradient, can occur through channels or carrier proteins
facilitated diffusion
how is cholesterol transported
water soluble carrier
cell uses energy
active transport
spend most of their time in a closed state
gated channels
ICF is ___ of total body water volume
2/3
vesicles are formed spontaneously allowing the cell to take on fluid “drinking”
nonselective
what do mechanically gated channels respond to
physical force like temp or pressure
solution is isotonic then the cell
does not change
cell doesn’t use energy
passive transport
types of active transport
protein pumps and vesicular transport (exo and endo)
ECF is ____ of total body water volume
1/3
highly specific process that occurs in response to certain plasma membrane receptors activation
receptor mediated endocytosis
the solution is hypertonic then the cell
shrinks
flux depends on
concentration gradient and membrane permeability
majority of biological molecules are not lipophilic T/F
true
2 forms of carrier mediated transport
facilitated diffusion and active transport
passive permeability of the membrane is determined by
structure of phospholipid bilayer
spends most of their time with their gate open
open channels
solution is hypotonic then the cell
swells
most common secondary active transport system are driven by
Na+
can use simple diffusion is called
lipophilic
energy from active transport comes from
ATP
H2O moves by osmosis in response to
total concentration of particles in the solution
water can cross all cell membranes with few exceptions T/F
True
osmolarity
a colligative property of solutions and depends only on the number of particles per liter of solution
tonicity is considered to be a ____ term
comparative
difference between tonicity and osmolarity
tonicity has no units, is only a comparative term, describes only the solution, and tells you what happened to cell volume at equilibrium. Osmalrity alone does not tell you what happened to the cell
protein-mediated transport can be either
passive or active
types of passive protein mediated transport
facilitated diffusion, aquaporins, and ion channels
types of active protein mediated transport
primary or secondary
Conversion of imported glucose into glucose 6-phosphate keeps intracellular glucose concentrations low so that
diffusion will never reach equilibrium
Example of a secondary active transporter
SGLT
Example of primary active transporter
Na-K-ATPase
Na-K-ATPase
permits electrical signaling in neurons and muscles cells, as well as drive passage of other solutes by secondary active transport
Cholesterol must be carried by an LDL- bind and internalize it through
receptor mediated endocytosis
Molarity=
moles of solute/ liters of solution
osmolarity is temperature
dependent ( high temp=high volume)
