Download A chef peels several cloves of garlic for use in a recipe. The chef

A chef peels several cloves of garlic for use in a recipe. The chef
puts the peeled garlic in a plastic bag and places the bag in the
refrigerator. Several hours later, the chef opens the refrigerator
and observes a strong smell of garlic. Through what process
were molecules able to pass through the plastic bag?
A
B
C
D
osmosis
diffusion
cell division
photosynthesis
Bellwork 11-30-16
Bellwork Review
A chef peels several cloves of garlic for use in a recipe. The chef puts the
peeled garlic in a plastic bag and places the bag in the refrigerator. Several
hours later, the chef opens the refrigerator and observes a strong smell of
garlic. Through what process were molecules able to pass through the
plastic bag?
A) osmosis- Incorrect, osmosis is the diffusion of water.
B) diffusion- Correct, the particles of garlic that moved through the bag
moved from an area of high concentration (lots of garlic) to areas of low
concentration (not much garlic) and will continue to move until equilibrium
(equal amounts everywhere) is reached
C) cell division- incorrect, this is the process by which cells create new cells.
D) photosynthesis-incorrect, this is the process by which plants use sunlight
to create food for the plant cell.
Objectives
Students will be able to analyze how plant and animal
cells are organized to carry on the processes of life.
SPI 7.1.5 Explain how materials move through simple
diffusion.
Success Criteria: I can explain simple diffusion and
osmosis.
Diffusion Lab Questions- Answer in your
notebook.
1.
2.
3.
4.
5.
The plastic bag is semipermeable to which substance?​
Why did the iodine enter the bag?​
Why didn’t the starch enter the beaker?​
How is the plastic bag like the cell membrane?​
What is the definition of the word “diffusion”?
Question...Elbow Partner
In diffusion and osmosis, why do the particles move from
areas that are more crowded to areas that are less crowded?
For a cell to survive, the amount of molecules need to be the same
on both sides of the cell membrane. If the cell does not pump out all
of its extras to even things out, this could be very bad. The cell can
swell up and explode.
Listen to this…
TOC: Diffusion & Osmosis Notes
What is Diffusion? -only write down the bolded teal sentences.
The movement of particles from regions or areas of
HIGH concentration (crowded) to areas of LOW
concentration (less crowded) is called DIFFUSION.
Look at Figure 1 on pg. 78!
The dye moved from an area of high concentration
and spread to the area of low concentration. Why?
Ex: when oxygen diffuses into the cell and carbon
dioxide diffuses out.
Equilibrium
• Sugar molecules, initially in a
high concentration at the
bottom of a beaker, will move
about randomly through
diffusion and eventually reach
equilibrium.
• Equilibrium: The concentration
is the same throughout or on
both sides of a semi-permeable
membrane.
• Diffusion occurs naturally
because of the kinetic energy
the molecules possess.
Diffusion of Water
Diffusion also happens with and between living cells.
The cells of organisms are surrounded by and filled with fluids
that are made mostly of WATER.
The diffusion of water through a SEMI-PERMEABLE (partially
allows things through) membrane is so important that it has
been given a special name- OSMOSIS. Video1 Video2
Look at Figure 2 on pg. 79!
Moving Small Particles
In a cell, the movement of particles across a cell membrane WITHOUT the use of
energy by the cell is called PASSIVE TRANSPORT.
During passive transport, particles move from an area of HIGH concentration to
an area of LOW concentration.
Examples:DIFFUSION & OSMOSIS
A process of transporting particles that requires the cell to use energy is called
ACTIVE TRANSPORT.
Active transport usually involves the movement of particles from an area of LOW
concentration to an area of HIGH.
This happens a lot in neurons. The membrane proteins are constantly pumping
ions (atoms or molecules that have a + or – electrical charge) in and out to get
the membrane of the neuron ready to transmit electrical impulses.
Moving Large Particles
•The active transport by which a cell surrounds a large particle, such
as a large PROTEIN, and encloses the particle in a vesicle to bring the
particle into the cell is called ENDOCYTOSIS.
•Vesicles are SACS formed from pieces of cell membrane.
•
Ex: when iron diffuses into the cell using active transport because the iron
molecules are too large.
•When large particles, such as WASTE, leave the cell, the cell uses an
active transport called EXOCYTOSIS.
•During exocytosis, a vesicle forms around the large particle, carries
the particle to the cell membrane, fuses with the cell membrane, and
releases the particle outside of the cell.
If time left...
In your journals on the same page you took notes,
draw a picture that reprents diffuion or osmosis.
(Something is moving from high concentration to a
low concentration to reach equalibrium.) Write a
caption that explains how the pictures illustrates
diffusion or osmosis.
Exit Post-It
When is equilibrium reached during diffusion?
A when the concentration of a substance is higher inside a cell than
outside the cell
B when the concentration of a substance is lower inside a cell than
outside the cell
C when the concentration of a substance inside a cell is the same as
the concentration of the substance outside the cell
D when the concentration of a substance inside a cell becomes zero