Tonicity - AP Bio

what is the major difference between the three types of passive transport?

-diffusion is the simple movement of molecules across a membrane -osmosis is the movement of water across a membrane -facilitated diffusion is the movement of molecules across a membrane with the help of transport proteins

what are 4 similarities of the types of passive transport?

-they all do not require energy -they all move substances down a concentration gradient -they all are dependent on permeability of cell membrane -all substances move from high concentration to low concentration to create a state of equilibrium

what is diffusion?

1) the movement of particles due to random motion, from an area of high concentration to low concentration 2) the tendency for molecules to spread out evenly into the available space, over time

what are the two goals of passive transport?

1) to maintain homeostasis - by making sure that the internal conditions of the cell are stable 2) reach an equilibrium of substance - an equal amount of substance on either side of the cell membrane

how does water move (into or out of the cell) in a hypertonic solution? Why?

The hypertonic solution the cell is in means that the solute concentration in the solution is greater than the solute concetration in the environment. Therefore to create a state of equilibrium, the net movement of water is out of the cell, to balance the water and solute concentrations of the cell and solution

how does water move (into or out of the cell) in a hypotonic solution? Why?

The hypotonic solution the cell is in means that the solute concentration in the solution is less than the solute concetration in the environment. Therefore to create a state of equilibrium, the net movement of water is out of the cell to balance the water and solute concentrations of the cell and solution

what are the three types of passive transport?

diffusion osmosis faciliated diffusion

what is facilitated diffusion?

diffusion through selective transport proteins

where is the net movement of water in a hypotonic solution?

into the cell

hypo, hyper or iso? the concentration of solute is the same as the concentration inside the cell.

isotonic

hypo, hyper or iso? when injected into the body, it will not case cellular damage because no osmosis occurs.

isotonic

what type of osmotic pressure does a hypertonic solution have?

low osmotic pressure

what term describes an animal cell in a hypotonic solution?

lysed

what type of osmotic pressure does an isotonic solutiom have?

moderate pressure on both sides

where is the net movement of water in an isotonic solution?

no net movement

what term describes an animal cell in an isotonic solution?

normal

where is the net movement of water in a hypertonic solution?

out of the cell

what are the two types of membrane transport?

passive transport active transport

what term describes a plant cell in a hypertonic solution?

plasmolyzed

how does an electrical gradient affect the rate of diffusion and osmosis?

positively charged molecules have a faster rate than negatively charged molecules

what is tonicity

refers to relative solute concentration of two fluids

if red blood cells that contain 97% water and are placed in a salt water solution with 90% water, they will_______________?

shrink

what are 5 factors that affect diffusion and osmosis?

steepness of concentration gradient temperature size pressure gradient electrical gradient

what types of substances require facilitated diffusion to enter the cell?

substances such as ions, sugar and amino acids use this method because of their large size and polar characteristic

how does steepness of concentration gradient affect the rate of diffusion and osmosis?

the bigger the gradient, the faster the rate of diffusion

what is osmoregulation?

the control of water balance, necessary adaptaion for life

how does bulk flow affect water movement?

the mass movement of substances in response to pressure, gravity of external forces

how does a pressure gradient affect the rate of diffusion and osmosis?

the more pressure, the faster the rate

how does size affect the rate of diffusion and osmosis?

the smaller the molecules the faster the rate

what is osmosis?

the tendency of water to move from an area of high concentration to an area of lower free water concentration

how does the temperature affect the rate of diffusion and osmosis?

the warmer the temperature, the faster the rate

what happens to water movement when a cell and solution have reached a state of equilibrium?

there is no longer a concentration gradient, but that does not mean water ceases to move. water moves into and out of the cell at equal and random rates. the concentration gradient has ceased.

what term describes a plant cell in a hypotonic solution?

turgid

isotonic solution

A solution in which the concentration of solutes is equal to that of the cell in the solution.

hypertonic solution

A solution in which the solute concentration is greater than that of the cell in the solution.

hypotonic solution

A solution in which the solute concentration is less than that of the cell in the solution.

how does water move (into or out of the cell) in an isotonic solution? Why?

There is no net movement of water when a cell is placed in an isotonic solution because no concentration gradient exists. The solute concentrations of the cell and solution are equal and therefore, no net movement of water is required for the cell and solution to be in equilibrium

what is the called when there is a difference in the amount of substance on either side of your cell's membrane called?

a concentration gradient

how does unequal concentration affect water movement?

a concentration gradient is present and a state of equilibrium can not be reached

what type of solution do plant cells 'like' to be in? why?

a hypotonic solution. plants prefer hypotonic environments because the water from environment gets soaked up by the cells and stored in the vacuoles. The vacuoles then apply turgor pressure to the cell walls which help plant cells maintain their structure.

how do materials move?

a process called passive transport

what is passive transport?

a process that does not require energy, particles move down a concentration gradient from an anrea of high concentration to low concentration

What is the U-tube experiment?

a u shaped tube with the two sides separate by a semi-permeable membrane. certain amounts of water and solute are placed on each side of the tube. if the membrane is permeable to the solute than the solute diffuses through the tube and an equilibrium is reached. if the membrane is not permeable to the solute than the solute does not diffuse through the tube and an equilibrium is not reached.

what do free water molecules move in response to?

an area were there is a high polar, ionic solute concentration

what are the three cases when water will move?

bulk flow unequal concentration high polar solute

what is osmotic presure?

cellular water pressure

what are the two types of transport proteins involved in facilitated diffusion?

channel proteins carrier proteins

what do channel proteins do in facilitated diffusion?

create a tunnel passageway for substances to move through

what term describes an animal cell in a hypertonic solution?

crenated

what determines the movement of water?

depends on location of where lower amount of free water molecules is located (relative to inside versus outside of cell)

what term describes a plant cell in an isotonic solution?

flaccid

what do carrier proteins do in facilitated diffusion?

form binding sites for molecules to bind to. the carrier proteins than change shape and allow the molecules to enter the cell after leaving the binding site.

what type of osmotic pressure does a hypotonic solution have?

high osmotic pressure

hypo, hyper or iso? putting a plant cell in this type of solution will result in a loss of water, a drop in turgor pressure or plasmolysis, causing the plant to wilt.

hypertonic

hypo, hyper or iso? the concentration of solute is higher than the concentration inside the cell.

hypertonic

hypo, hyper or iso? The concentration of solute is lower than the concentration inside the cell.

hypotonic

hypo, hyper or iso? when a cell is placed in this solution, water will enter the cell by osmosis resulting in turgor pressure.

hypotonic

how does a high polar solute affect water movement?

water is attracted to polar substances and then becomes bound to them

which way would the water move if a potato slice is placed in pure water?

water moves into the potato slice

which way would the water move if vegetables are sprinkled with water?

water moves into the vegetables

which way would the water move if a cucumber slice is placed in water?

water moves out of the cucumber

which way would the water move if salt is poured on a snail?

water moves out of the snail