Download name______________________ date_________

Cell Transport
Diffusion is the net movement of particles from an area of high
concentration to an area of low concentration in other words the
particles move from an area where there are more of them to an area
where there are fewer.
Diffusion is a type of Passive Transport because no energy is needed to
move the particles because they are already in motion.
Concentration refers to the amount of a substance in an area.
Diffusion can occur more quickly when concentration, temperature, or
pressure are high because the particles collide more often.
Examples of Diffusion in the body
a. Oxygen diffusing from the lungs into the blood so it can be
carried and diffused into the cells.
b. Carbon Dioxide from the cells in the body to the blood and then
the lungs so it can be diffused out to the environment.
Facilitated Diffusion is also Passive Transport because no energy is
required. Facilitated Diffusion is similar to Diffusion because the
particles will move from high to low concentrations. It is different
from Diffusion because Facilitated Diffusion will use proteins
embedded in the membrane to move particles into and out of the cell.
Example of Facilitated Diffusion in the body
a. In Animals, stored Glycogen (a polysaccharide) will be broken
down into Glucose (monosaccharide) and will move into the blood
and then transported into the cells through proteins in the
membrane.
1
Write a Summary
_____________________________________________________
_____________________________________________________
_____________________________________________________
_____________________________________________________
Define:
a. Diffusion _________________________________________________
b. Facilitated Diffusion_________________________________________________
On Lab, page 1 answer 1,4,5 (wait on 2,3)
Page 2 answer what’s in the bag? 1,2
Make predictions 1,2,fill out data table
Complete post lab and use colors for number 5.
2
Osmosis
Water is important to maintaining homeostasis in living organisms.
Water helps to breakdown biomolecules in the process of Hydrolysis.
Water is used by plants in photosynthesis to make Glucose. Water also
keeps organisms hydrated.
The movement of water is passive and called Osmosis. Water will move
from high concentrations to areas of lower water concentrations or
down the gradient. Think about a spill on the counter and a paper towel.
Why does the water get absorbed by the paper towel? Because it is
the area of no water concentration?
Three conditions of osmotic solutions
a. Isotonic- equal amounts of water in the cell and in the
environment. Water is still moving but the rate is equal so you
cannot detect a difference in concentration. Animal cells prefer
this condition because they do not have large vacuoles or a cell
wall to contain the excess water.
b. Hypotonic- there will be more water in the environment than
inside the cell. Therefore the cell must have more dissolved stuff
in it called solutes than the environment has in it. This is the
condition plant cell prefer because water is used during
photosynthesis and plants will lose water during transpiration. If
plants do not have water, they cannot make their food.
Example of Hypotonic in the human body
When a person suffers from kidney failure they cannot remove excess
water from the blood so there body fills up like a water balloon. The
dialysis machine filters the blood removing excess water and waste
since the kidneys are no longer functioning.
3
In plants, Hypotonic causes TURGOR PRESSURE- the central vacuole
swells and the cell becomes hard.
In animals, Hypotonic causes CYTOLYSIS-the animal cell swells and
then bursts.
c. Hypertonic-neither plants nor animals want to lose water.
Hypertonic conditions occur when there is more solute in the
environment and the cell will lose water trying to hydrate the
environment. In animals this would occur if we drank salt water.
In plants, Hypertonic causes PLASMOLYSIS- the plant cell
central vacuole shrinks and the cell collapses.
In animals, Hypertonic causes CRENATION-the animal cell will
shrivel up and collapse in on itself.
Write a Summary
_____________________________________________________
4
Osmosis and Tonicity
Define osmosis.
____________________________________________________
In which direction does water move across membranes, up or down the
concentration gradient?
_____________________________________________________
Define these 3 terms:
a. isotonic_____________________________________
b. hypertonic_____________________________________
c. hypotonic_____________________________________
Use arrows to show the direction of water movement into or out
of each cell. Color and label the cell in an isotonic environment light
blue, the hypotonic environment yellow, and the hypertonic environment
light green.
5
Match the description or picture with the osmotic condition:
A. Isotonic
B.
Hypertonic
C.
Hypotonic
_____ solution with a lower solute concentration
_____ solution in which the solute concentration
is the same
_____ condition plant cells require
_____ condition that animal cells require
_____ red blood cell bursts (cytolysis)
_____ plant cell loses turgor pressure
(Plasmolysis)
_____ solution with a higher solute
concentration
_____ plant cell with good turgor pressure
_____ solution with a high water concentration
6
Active Transport
Active transport moves particles from an area of low concentration to
an area of high concentration. This is also called moving up or against
the gradient.
Active transport will use pumps, vesicles, and proteins to push the
substances up/against the concentration gradient.
Two types of Active Transport that use Vesicles:
Endocytosis- in this process the cell surrounds a substance outside in
the environment by extending the cell membrane around the substance
and then pinches it off and brings the substance inside.
Ex:
Two types of endocytosis :
a. Pinocytosis- means the cell is drinking.
b. Phagocytosis-means the cell is eating..engulfing materials
Exocytosis- the opposite of Endocytosis. Instead of taking in materials
using vesicles it will expel materials by having the vesicles fuse with
the membrane and release the contents to the environment.
7
ACTIVE TRANSPORT using proteins as pumps
Proteins in the membrane will use ATP to have energy so it can pump
Calcium, Potassium, and Sodium ions across the membranes against the
concentration gradient. It takes ATP to move substances in the
opposite direction of the concentration gradient. The NA+/K+ (sodiumpotassium) pump is used to move ions across a membrane.
Write a Summary
_____________________________________________________
_____________________________________________________
_____________________________________________________
_____________________________________________________
8
Transport Requiring Energy
What type of transport is represented by the following picture?
_______________________
What energy is being used? ______________
In which direction (concentration gradient), is the movement
occurring? _________________
Describe the two types of Endocytosis?
_____________________________________________________
_____________________________________________________
_____________________________________________________
_____________________________________________________
9