Download Cell Membrane PPT

Eagle Zone
 -Turn in your current Event to the pink basket
 -Write down your homework in AGENDA: Complete “Cell City”
homework in your spiral-under Unit 3 on website
-Get out your notes spiral and be ready to take notes when
the bell rings.
 Announcements:
1. Project Due Next Wednesday by 4pm
2. Quiz over cell organelles and functions next Wednesday (Tues 8th)
3. Quiz over identifying organelles in a cell next Friday(Thurs 8th)
Cell Membrane
Outside
of cell
Proteins
Carbohydrate
chains
Cell
membrane
Inside
of cell
(cytoplasm)
Protein
channel
Lipid bilayer
TAKS
Objective 2 – The student will
demonstrate an understanding of living
systems and the environment.
TEKS Science Concepts
4 -The student knows that cells are the basic
structures of all living things and have specialized
parts that perform specific functions, and that
viruses are different from cells and have different
properties and functions.
(B) investigate and identify cellular processes
including homeostasis, permeability, energy
production, transportation of molecules, disposal
of wastes, function of cellular parts, and synthesis
of new molecules
Engage
Can you smell what is inside the balloon?
Eagle Zone
1)Give the function of the following cell
organelles AND tell what type of eukaryote
they are found in:

Golgi apparatus, ribosomes, mitochondria,
chloroplast
2)What three organelles are found in a plant
cell that are not in an animal cell?
3)What is the main difference between a
virus and a bacteria?
4)Why does a virus need a host cell?
– 15 minutes
Explore
Veggie Lab-Write the questions

Retrieve a piece of vegetable from the beaker labeled water.
Describe the following in your LAB BOOK:
• What does the vegetable look like? (color, shape, size, feel)
• Try to bend the vegetable. Describe what happens
• Which direction do you think the water traveled, inside or outside
of the cell membrane of the vegetable? Why?

When you are done with BOTH salt and tap water, answer these
questions:
• Define semi-permeability
• If water is moving across a membrane, what is the name of that
process?
Explain: Cell Diversity
Cells within the same organism show
Enormous Diversity in:



Size
Shape
Internal Organization
A. Cell Size
Female Egg - largest cell in the human body;
seen without the aid of a microscope
Most cells are visible only with a
microscope.
Why do you think most cells are so small?
Cells are small for 2 Reasons
Reason 1:

Limited in size by the RATIO between their Outer
Surface Area and Their Volume.
A small cell has more SURFACE AREA than a large
cell for a GIVEN VOLUME OF CYTOPLASM.
Cells are Small
Reason 2:
 THE CELL'S NUCLEUS (THE BRAIN)
CAN ONLY CONTROL A CERTAIN
AMOUNT OF LIVING, ACTIVE
CYTOPLASM.
B. Cell Shape
Diversity of form
reflects a diversity of
function.
THE SHAPE OF A
CELL DEPENDS ON
ITS FUNCTION.
C. Internal Organization
Cell membrane
Cytoplasm
Prokaryotic Cell
Cell membrane
Cytoplasm
Eukaryotic Cell
Nucleus
Organelles
 Semi-Permeable-allows
some materials to pass through
membrane to cell while others
are not capable
 Selectively Permeable
 Amphipathic~
hydrophobic &
hydrophilic regions
 Fluid Mosaic Model
Membrane
structure
The Structure of the Cell Membrane
Outside
of cell
Proteins
Carbohydrate
chains
Cell
membrane
Inside
Protein
of cell
(cytoplasm) channel
Lipid bilayer
Explore 2
Cell Membrane Manipulative


In groups, you will construct a model of the cell
membrane using the materials provided for you
at the table
Once you have constructed your model, have it
examined by the teacher for completeness.
Each person in your group must say at least 1
thing about the model before your group can be
awarded completion points on your lab ticket
Membrane traffic
Passive transport~ diffusion
of a substance across a
biological membrane
(NO ENERGY)
Diffusion~ particles
movement from
high concentration to
low concentration

Osmosis~ the diffusion of
water across a selectively
permeable membrane
Results of Diffusion
Dynamic equilibrium

Once diffusion has evenly distributed the
particles; movement of particles continues with
no change in concentration
Homeostasis

Preservation of equilibrium
Diffusion depends on
Concentration gradient
Concentration gradient: the difference in
concentration of a substance across space
Diffusion is said to move down a
concentration gradient
Diffusion continues until there is NO
concentration gradient
Ex: O2 diffuses into oxygen depleted blood
Diffusion
molecules like WATER,
OXYGEN, AND CARBON
DIOXIDE can move in and out
freely.
Small
Large
molecules like
PROTEINS AND
CARBOHYDRATES CANNOT
Charged
IONS CANNOT
QuickTime™ and a
Cinepak decompressor
are needed to see this picture.
Osmosis~ the diffusion of water across a
selectively permeable membrane
Small quiz- use white boards
Osmosis is the diffusion of _______ across a cell
membrane.
Osmosis and Diffusion are both types of
__________ transport.
Passive transport does or does not require energy?
Small molecules can not move across freely. T or F
Large molecules can move freely. T or F
Three Different Types of
Solutions
Isotonic Solution
Hypotonic
Solution
Hypertonic
Solution
Isotonic Solution
The solute outside the cell is equal in
concentration to the solute in the cell.
The cell retains its shape.
water moves equally in both directions
Hypotonic Solutions
Solution outside the blood cell contains a lower [] of
solute than inside of the cell.
Water will diffuse in.

cell will lyse (burst).
Animal cells - cytolysis.
 Plant cells do not burst- turgur pressure—
grocers use this idea
Cells in a Hypotonic Solution
Hypertonic Solutions
The solution outside the cell has a higher [] of
solute than inside of the cell.
Water will diffuse out of the cell,


causing the cell to shrink
or crenate
Why should you not salt meat before cooking?
CRENATION
PLASMOLYSIS
Cells in a Hypertonic Solution
Review:
In what type of solution would these
cells be found?
Water balance Summary
Plasmolysis
QuickTime™ and a
Cinepak decompressor
QuickTime™ and a
are needed toCinepak
see thisdecompressor
picture.
are needed to see this picture.
Turgidity
Elaborate
Semi-Permeability Lab
Eggactly What I Predicted
Eagle Zone
Your test over Unit 3 will be Monday (B
day and 8th period) and Tuesday (A day)
Get ready for the scavenger hunt!! You
need something to write with
Winner will receive prize tomorrow