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