Membranes & Materials Movement
select all statements that describe both dialysis and osmosis
-across a semi-permeable membrane -movement from high to low concentration -does not require external energy input
receptor-mediated endocytosis
-highly regulated form of pinocytosis -receptor proteins embedded in the plasma membrane bind to specific extracellular molecules and signal internalization -endocytosis that transports a specific molecule using a membrane protein signal
which characteristics describe both dialysis and facilitated diffusion?
-move from greater to lesser concentration -diffusion across a semi-permeable membrane -no external energy required
when all protein carriers are saturated, increasing the concentration gradient of the molecule needing transport will ______.
-not change the rate of diffusion -maintain saturation
how do protein channels and protein carriers differ?
-protein channels do not bind to the transport molecule -protein carriers can transport larger molecules than protein channels
A woman receives a bouquet of flowers. She adds the entire package of "plant food" to the water in her vase, mixes, and then places the flowers into the vase. Because she added the entire package, the concentration of "plant food" in the vase solution is greater than a normal plant cell's solute concentration. Select all answers that accurately describe this situation:
-the flowers are hypo osmotic to the solution -the flowers are in a hypertonic solution -the flowers will lose water to the vase solution and wilt
exocytosis
-the release of hormone by a cell -a cell delivers specific molecules, fluids, and large materials to the fluid outside the cell
equilibrium
at equilibrium molecules continue to collide and move in all directions, but identifying the original sources position of the molecules is difficult because a concentration gradient no longer exists.
pinocytosis
endocytosis that transports extracellular solutes
active and passive transport differ in that active transport requires _______.
energy expenditure by the cell
phagocytosis
engulfing bacteria
a small hydrophilic ion such as sodium ion could move across the plasma membrane along its gradient by _______.
facilitated diffusion
the typical function of the kidney is to ______.
filter excess fluid and electrolytes from blood
endocytosis
formation of a vesicle containing plasma membrane lipids
fewer molecules move from a region of low concentration to a high concentration because molecules in the lower concentration area _____.
have fewer molecular collisions than molecules in the higher concentration area
organisms living in salty environments such as the ocean must protect their cells from _________.
losing too much water to the environment
what decreases the rate of molecular collisions?
low temperature
What forms a traveling plume of molecules?
mixing
a bag of tea is placed into a cup of hot water. The tea molecules visibly spread from the tea bag into the water because ______.
molecules are moving in all directions, but more molecules are moving away from the bag than toward the bag
osmosis may be best be described as the ______.
movement of water across a membrane
what happens to a blood cell placed into a hypotonic solution?
net water moves into cell
what happens to a plant cell placed into a hypotonic solution?
net water moves into cell
what happens to a blood cell placed into a hypertonic solution?
net water moves out of cell
when sugar is mixed with water, equilibrium is reached when ____.
the dissolved sugar molecules are evenly distributed throughout the solution
the energy for transport of molecules through facilitated diffusion is obtained from ______.
the existence of a favorable concentration gradient for the molecule being transported
T/F: because dialysis involves an artificial membrane, substances (solutes) must be added to the dialysis fluid to prevent the removal of too many solutes from the blood
true
the primary difference between facilitated diffusion are active transport is whether a membrane protein _______.
uses external energy to facilitate movement
facilitated diffusion _______.
uses protein carriers to transport molecules
secretory vesicle
vesicle that fuses with the plasma membrane
what happens to a plant cell placed into an isotonic solution?
water movement is equal both directions
an animal cell is placed into a solution containing 1% solute. IF the animal cell contains 1% solute, which of the following statements is FALSE?
water will not move across the membrane
when do molecules travel more rapidly?
when concentration differences are large -a large concentration difference creates a steep (strong) gradient that permits rapid diffusion
a large hydrophilic molecule could enter a cell by moving against its gradient using __________.
active transport
calcium ions may be moved into a concentrated area by _______.
active transport
which transport method is used when a cell must move molecules against a concentration gradient?
active transport
Which type of molecule is most likely to diffuse easily across a cell membrane?
a small hydrophobic molecule
What determines the direction of molecular motion?
concentration gradient
osmolarity
describes the concentration of solute molecule present in a liquid
how is dialysis similar to body function?
dialysis removes body wastes
a steroid delivered by the bloodstream needs to enter a cell. The concentration of the non polar steroid is lower on the inside of the cell. The steroid enters the cell by ________.
direct diffusion
What increases the rate of diffusion?
high temperature
T/F: For excess fluid to bereaved from a patient's blood during dialysis, the patient's blood must be _______.
hypo osmotic (hypotonic) to the dialysis fluid
a drug that disassembles the cytoskeleton is applied to a sample of cells. Which of the following processes is most likely to be affected?
intracellular transport
what increases the rate of collision between molecules?
raising temperature -raising temp also affects the kinetic energy of the collision between molecules
dialysis
refers to the diffusion of solutes (molecules dissolved in a solvent) directly through semi-permeable membranes
vesicle
sphere with a single phospholipid bilayer
molecules of liquids and gases ____.
spread throughout the available space
