Analogy
A similarity between like features of two
things, on which a comparison may be
based.
Examples:
A POMEGRANTE
A LIVING CELL
ANOTHER ANALOGY
WATER GUN
HEART
UNIT 4:
Cell Transport
(Section 7-3)
The transportation of food, ions, water and
wastes (which are all made up atoms and
molecules) across the cell membrane.
What makes a stable environment?
Homeostasis
• The body’s maintenance of a stable,
internal environment.
– Dynamic
• When are you not at homeostasis?
– Fever
– Cold
– Hot
– Etc.
IF WE GO
CLOSER,
WHAT DO
WE SEE?
Interest Grabber
In or Out?
Section 7-3
How is a window screen similar to a cell membrane?
1. What are some things that can pass through a
window screen?
2. What are some things that cannot pass through a
window screen? Why is it important to keep these
things from moving through the screen?
3. The cell is surrounded by a cell membrane, which
regulates (controls) what enters and leaves the cell.
Why is it important to regulate what moves into and
out of a cell?
Particles (O2, CO2, salts, sugars,
amino acids) pass into and out of
or cells.
Fluid Mosaic Model of the Cell
Membrane
Section 7-3
• A MODEL that shows that our cells are composed of lipids,
carbohydrates, protein and water.
Outside
of cell
Proteins
Carbohydrate
chains
Cell
membrane
Inside
of cell
Figure
7-12
(cytoplasm)
Protein
The
Structure of the CellLipid
Membrane
bilayer
channel
Cell Membrane
Carbohydrate
Proteins chains
Cell
membrane
Protein
channel
Lipid bilayer
http://www.stolaf.edu/people/giannini/flashanimat/lipids/membrane%20fluidity.swf
(cell membrane animation)
The cell membrane is…
1. An organelle
2. Made up of a phospholipid bilayer.
3. Semipermeable- very selective so certain
molecules can pass through.
4. Responsible for helping us breath.
Too much or too little of a good
thing…
http://www.daylife.com/photo/04uC7mB7Ueg9b too much water follow up
• Solvent- water can
dissolve just about
anything.
• Solute-anything (ex.
salt, sugar) that is
dissolved by water.
ATP (Energy) Molecule- when need energy to do
work, certain enzymes release the energy stored
in the chemical bonds in ATP.
Adenine
Ribose
3 Phosphate groups
Two types of Cell Transport
Passive Transport
Some solutes (sugar,
salts) will need NO
ENERGY to move
themselves through the
cell.
Active Transport
Some solutes will
need ENERGY to
move themselves
through the cell.
1. Diffusion
2. Osmosis
3. Facilitated Diffusion
1. Endocytosis
2. Exocytosis
Diffusion-movement of particles
from a high to a low concentration.
Can you smell it; is the kool-aid entirely purple
???????
Facilitated Diffusion -when the cell
membrane protein helps diffuse
glucose across cell membrane.
Section 7-3
Glucose
molecules
High
Concentration
Cell
Membrane
Low
Concentration
Protein
channel
Please write down 3 questions
about this picture.
What dangers does chemical spills
pose to your cells?
• Why is it important to
were protective gear?
• What forms of matter
are chemicals in?
• How do chemicals get
inside your cells?
Osmosis-The movement of water from a
lower to a higher concentration until solutes
Section
7-3
even
out.
Osmotic Pressure -movement of
water from a low concentration to a
high concentration.
Hypotonic
Solution
Isotonic
Solution
Hypertonic
Solution
High extracellular soluteEqual movement of
Low extracellular solute
water flows out.
solutes are equal
water flows in.
intr/extr.
For organisms to survive, they must have a way to balance the intake and loss of
water.
Active Transport through Cell
Membrane
•
E is needed for particles to move across cell
• Includes protein pumps
• Endocytosis- movement of solid liquid
particles into the cell.
• Exocytosis- movement of solid and liquid
out of the cell.
exocytosis
What type of cell transport is this?
Molecule to
be carried
Energy
Molecule
being carried