Warm up
What is the relationship of the
structure and function of a cell?
Objective:
• Develop, communicate, and justify an
evidence-based scientific explanation
regarding cell structures, components, and
their specific functions
• Cells are the smallest unit of life that can
function independently and perform all the
necessary functions of life
Lab
• What do you think could happen to this egg if
we sit it in a liquid for a while?
• One side, fill out KWL Chart then scavenger
hunt
• Lab on the other side
Step 1:
• Draw a picture of osmosis
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Groups of 4:
1. Supplier: get packet for group
2. Answer pre-lab questions
3. Captain: Please get Raw egg, 300 ml vinegar,
tap water, salt water, and a liquid of your choice,
metric tape, balance, plastic container to hold
egg, beaker, marker, masking tape
Exit:
• Draw a picture of osmosis
Warm up:
• How are the components – or organelles – of
a cell related to the cell’s function?
Objective
• Develop, communicate, and justify an
evidence-based scientific explanation
regarding cell structures, components, and
their specific function
• The purpose is to know that cells are the
smallest unit of life and can function
independently and perform all necessary
functions of life
Vocabulary
• Active transport
• Passive transport
• Directions: Draw a picture of what you think
these are.
• Find context clues to find definition. Then
discuss in groups.
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While active transport requires energy and work, passive transport does not. There are several different types of this easy
movement of molecules. It could be as simple as molecules moving freely such as osmosis or diffusion. You may also see
proteins in the cell membrane that act as channels to help the movement along. And of course there is an in-between
transport process where very small molecules are able to cross a semi-permeable membrane.
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Sometimes, proteins are used to help move molecules more quickly. It is a process called facilitated diffusion. It could be as
simple as bringing in a glucose molecule. Since the cell membrane will not allow glucose to cross by diffusion, helpers are
needed. The cell might notice outside fluids rushing by with free glucose molecules. The membrane proteins then grab one
molecule and shift their position to bring the molecule into the cell. That's an easy situation of passive transport because the
glucose is moving from higher to lower concentration. It's moving down a concentration gradient. If you needed to remove
glucose, the cell would require energy.
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Letting Concentration Do the Work
Sometimes cells are in an area where there is a large concentration difference. For example, oxygen molecule
concentrations could be very high outside of the cell and very low inside. Those oxygen molecules are so small that they are
able to cross the lipid bilayer and enter the cell. There is no energy needed for this process. In this case, it's good for the cell
because cells need oxygen to survive. It can also happen with other molecules that can kill a cell.
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Osmosis
Another big example of passive transport is osmosis. This is a water specific process. Usually, cells are in an environment
where there is one concentration of ions outside and one inside. Because concentrations like to be the same, the cell can
pump ions in an out to stay alive. Osmosis is the movement of water across the membrane.
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For a cell to survive, ion concentrations need to be the same on both sides of the cell membrane. If the cell does not pump
out all of its extra ions to even out the concentrations, the water is going to move in. This can be very bad. The cell can swell
up and explode. The classic example of this type of swelling happens when red blood cells are placed in water. The water
rushes in to the cells, they expand and eventually rupture (POP!).
Active transport
• Active transport refers to movement of
materials from an area of lower concentration
to an area of higher concentration, against the
concentration gradient. To do this, energy is
required, usually from ATP. Cell membrane
pumps, endocytosis and exocytosis (the focus
of the previous lesson) all aid in active
transport.
Passive transport
• Passive transport is the movement of
substances across the membrane without any
input of energy from the cell. Osmosis and
diffusion (the focus of the previous lesson) are
two examples of passive transport.
Drawing
• Draw a picture of what these vocabulary
words are and write a sentence with it.
Take pre-quiz
• How does this relate to objective?
Activity
• Pass students the stack of game cards, face
down, and randomly choose their roles in the
game by choosing a card.
• place the placards around their necks so
everyone knows their roles in the game
Activity continued
• students who have drawn similar cards to
group together to talk about their strategy for
movement into the cell membrane.
• look over the activity sheet to review what
type of transport they are able to participate
in each time.
• have members of the lipid bilayer and the
proteins discuss placement of their proteins
within the membrane
Activity
• announcing which transport type will be illustrated
• "Red Rover," the particles try to enter the cell and still be
aware of the dynamic equilibrium that takes place in
conjunction with the concentration gradient.
• Have the cell membrane hold hands so as to be "fluid"
enough for small particles such as water, carbon dioxide
and oxygen gas to enter and exit the cell at will, while
charged particles must enter and exit the cell only through
their specific channel proteins.
• Have the channel proteins announce which specific ion
they allow to enter and exit.
• Have the carrier proteins also announce their specific
molecule, such as glucose or amino acids.
Quiz
• Take quiz
Active and passive transport
• https://www.youtube.com/watch?v=ovHYKlH
YpyA
Exit
• Predict what would happen to a blood cell if
placed in liquids similar to the ones in which
the egg was submerged. Explain why salty
foods make you thirsty