Download 2.3 Cellular Transport

“Materials move across
the cell’s membranes”
Section 2.3
Do Now
• What is the purpose of the cell membrane
in a cell?
• What goes in and out of our cells?
• Why are our membranes important?
Objectives
• To explain the different functions of the
macromolecules in the plasma membrane.
• To understand the process of diffusion.
• To compare and contrast active and
passive transport.
Membranes
• “Fluid Mosaic Model”
Membrane Components
• Phospholipids:
– Gives the general structure of the membrane
Membrane Components
• Proteins: allow bigger substances to pass
through, also provide structure
Membrane Components
• Cholesterol: helps maintain structure of
phospholipids, prevents them from sticking
Membrane Components
• Carbohydrates: receptors that send and
receive signals.
Simulation Activity
• Everybody Stand up!!! Lets make a
membrane out of the desks.
• I need 4 volunteers (1-H2O, 3-Glucose)
Types of Transport
• Passive Transport
• Active Transport
• Vesicular Transport
Passive Transport
• Do NOT require energy
• Go from an area of high concentration to
an area of low concentration
• “Go with the flow”
3 Types of Passive Transport
• Diffusion
• Facilitated Diffusion
• Osmosis
Diffusion
• Molecules move from a high concentration
to a low concentration to create DYNAMIC
EQUILIBRIUM.
Effected By…
• Heat- higher temp increases rate
• State of Matter
– Solid- slow
– Liquid- faster
– Gas- fastest
• Size and Concentration
– Bigger= slower
– More concentration = faster
Perfume Demo
Food Coloring Demo
Facilitated Diffusion
• the molecules need a “helper” or
“facilitator” to allow them to cross the
membrane when they are too big.
Do NOW
• What is passive transport?
• What are 2 examples of passive
transport?
• Explain what happens when you put a
sugar cube in your tea in regards to
diffusion.
Objectives
• To understand how the process of
Osmosis works.
• To explain the different types of solutions
• To compare and contrast endocytosis vs.
exocytosis.
Osmosis
- The flow of WATER from a high
concentration to a low concentration
- Occurs based on the types of solutions
you are working with.
Solution
- A) a mixture in which you cannot separate
the components (ex: Kool aid)
- i. solute: the substance being dissolved
- Ex: kool aid powder
- Ii. solvent: The substance doing the dissolving
- Ex: water
Solutions
- Solutions can be…
- Isotonic
- Hypertonic
- hypotonic
Isotonic Solutions
• Same amount of solute inside the
membrane as there is outside.
• Cell in this solution: NOTHING 
Plant Cell
Blood Cell
11,397x
HYPERtonic Solutions
• More solute, less solvent
• Cell in this solution:shrinks/shrivels 
“Plasmolysis”
“Crenates”
HYPOtonic Solutions
• Less solute, more solvent
• Effect: cell swells or bursts! /
High or low Solute?
Cell in ________
Solution
H2O
H 2O
Cell in ________
Solution
H 2O
H 2O
Cell in ________
Solution
H 2O
H 2O
Scenario 1
A salt water fish is put into a
freshwater aquarium.
• What type of
solution is the
freshwater?
• What is going to
happen to the cells
of the fish?
Scenario 2
A patient is given an IV, which contains the
perfect balance of glucose
• What type of
solution is in the
IV?
• What is going to
happen to the cells
of the human?
Scenario 3
Your garden is infested with slugs so
you go around pouring salt on them
• What type of
solution is this salt?
• What is going to
happen to the cells
of the slug? (don’t
do this to the poor
slugs )
Practice
• By yourself or with a partner (anyone),
work on the diffusion problems.
• First try to do this by yourself, then verify
your answers with a partner. Try to help
each other. If you are confused, raise your
hand and I will come help you!!
• If you finish early, try to answer the “Think
about it” questions on my desk! If you don’t
finish, please finish it for homework.