Download Cell Membrane and Transport (1)

Mr. Moore
Biology
Cell Membrane & Transport
Chapter # ________ Pages # _______
1
Rewind Your Mind
Match the Organelle with the proper term or phrase
1.
2.
3.
4.
5.
6.
7.
8.
Plasma Membrane
Mitochondria
Chloroplast
Vacuole
Nucleus
Ribosome
Cell Wall
Lysosome

Made of Cellulose
Cellular Respiration
“Selectively Permeable”
1 Large in plant cells

Stores protein instructions

rRNA
Filled with enzymes
Collects Sunlight Energy





2
Year in Progress
Scientific Method
Eukaryotic Organelles (Cell Membrane)
Cells (Prokaryotic vs. Eukaryotic)
Macromolecules
Molecules (H2O)
Basic Chem.
Characteristics
Of
Life
3
Vocabulary
Write these words and their meanings on page ___ of your notebook:
Prefix/Suffix
Meaning
Examples
Im-
Not
Impermeable, Impartial
Semi-
Partially
Semi-permeable
Hypo-
Less than
normal
Hypotonic
Hyper-
More than
normal
Hypertonic
Iso-
equal
Isotonic Solution
Quiz on these words: __________
4
Cell Membrane &
Passive Transport
5
Cell Membrane

The cell membrane performs many
functions…including a protective barrier,
an entrance for needed materials (and exit
for unwanted wastes!), and a signal
acceptor/ transmitter.
6
Vocabulary:
Semi-permeable
An object that is permeable allows ALL
things threw (Open Door)
 An object that is impermeable allows
NOTHING threw (Closed Door)
 Cell Membranes are considered “Semipermeable”; allowing SOME things threw,
while keeping others out (Screen Door)

7
Diffusion and Osmosis


The Cell must maintain homeostasis (internal
balance) to remain alive!!
By the cell membrane being “semi-permeable”
and regulating what goes in and out of the cell
(By processes of Diffusion and Osmosis), the
cell can maintain homeostasis.
8
Diffusion

The process by which molecules spread
from areas of high concentration to low
concentration areas. (Down Concentration
Gradient.)

This process requires no “new” energy
and is referred to as PASSIVE
TRANSPORT
9
Osmosis
Specific type of diffusion…
Osmosis: “diffusion of water”
 Follows the same rules as diffusion, but
term used only when talking about water
(H2O)!

10
Vocabulary:
Concentration Gradient



Concentration: The amount of a substance in a
given area.
Gradient: The slope connecting 2 locations with
varying amounts of a substance.
Concentration Gradient:
The slope showing varying amounts of a
substance in 2 locations
Areas simply referred to as High (more of a
substance) and Low (less of a substance)
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Concentration Gradient
10
9
High
8
7
6
5
4
3
2
1
Low
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13
Passive Transport

Passive Transport: Movement of particles
by simple diffusion from “High” to “Low”.
“Passive is laid back!!!!”

Examples: Diffusion, Osmosis (water), and
some Facilitated Diffusion
14
Facilitated Diffusion

Facilitated Diffusion: The transport of
materials across the plasma membrane
with the aid of Proteins.
A Type of Protein!!!
15
Facilitated Diffusion

Facilitated diffusion is a common way of
moving sugars (C6H12O6) and Amino Acids
across a membrane.
16
Facilitated Diffusion:
Proteins

Channel Proteins- Provide the openings
through which small, dissolved particles
(Especially Ions!) diffuse by passive
transport!
17
Equilibrium


When the concentration of the molecule is the
same throughout space.
Active transport continues until Equilibrium is
reached!
18
Outcomes of Diffusion or Osmosis

There are 3 different “solutions” that a
cell can be placed in to cause Diffusion
or Osmosis:
1. Hypotonic Solution
2. Hypertonic Solution
3. Isotonic Solution
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Hypotonic




Cell has less water
and too much solute.
Water moves into the
cell and solute moves
out… (Causing
Swelling!)
Can lead the cell to
denature (burst!)
Think Hippo!!!
20
Hypertonic



Cell has Too much
water and low
amounts of solute.
Water moves out of
the cell, and solute
moves in… (Causing
wrinkles!)
Can lead cell to
denature (shrink!)
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Isotonic

The amount of water and solutes is at equilibrium
inside and outside the cell!
22
Practice “Solution”
Rules:
1. draw circle inside
square
2. label the higher
concentration of
water
3. draw arrow from
high to low
Example:
Cell with 20% solute is
placed into solution
with 40% solute.

100
H
100
-20
80
-40
60
L
Water Leaving: Hypertonic!
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Practice Problem

What would happen if
you placed a cell with
20% solute into
distilled (pure) water?

The solution is
Hypotonic, and the
cell would swell up
(get bigger)!
24
Practice Problems
25
EOC Practice Problem

A person with swollen gums rinses his mouth with warm
salt water, and the swelling decreases. Which has
occurred?
A. The swollen gums have absorbed the saltwater
solution.
B. The saltwater solution lowers the temperature of the
water in the gums.
C. The salt in the solution has moved against the
concentration gradient.
D. The water in the gums has moved from a high to a low
concentration of water.
26
EOC Practice Problem

Which is an example of osmosis?
A. potassium ions moving in and out of an
animal cell
B. carbon dioxide moving into the leaf cells of a
plant
C. oxygen moving into the bloodstream from the
lungs
D. water moving into the root cells of a plant
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Rewind Your Mind

List as many organelles
and their functions as you
can…
•Nucleus: Control center

Why do they say it is
sooo bad to drink salt
water if stuck at sea?
What happens to you?
•Cell Membrane: Screen Door • Your cells have more
pure water in them then
•Mitochondria: Cellular Resp.
the salt water your
•Chloroplast: Photosynthesis
drinking. Water leaves
your cells (Hypertonic
•Vacuole: Storage
solution) and your cells
•Lysosome: Suicide Sac
shrink. You die from
DEHYDRATION!!
•ER: Transport……
28
Cell Membrane &
Active Transport
29
Cell Membrane Basics

“Phospholipid Bilayer” …Two layers of a
single phosphate connected to 2 lipids.

This model is referred to as the “Fluid
Mosaic Model” because the phosphates
are not connected, and can move around.
30
Cell Membrane Basics

Because the phosphates are not “stuck”
together, several different types of proteins
are able to drift around the surface of the
cell….
“Like icebergs floating in the sea”
31
Vocabulary:
Selectively Permeable
Because phospholipids can move around,
they can let stuff in OR move stuff out.
 Selective: To choose to allow
 Permeable: To allow to pass threw
Selectively Permeable:
To allow some molecules to pass, and not
other molecules

32
Active Transport

By the cell membrane being “Selectively
Permeable” and somewhat regulating what goes
in and out of the cell (By processes of Active
Transport), the cell can again maintain
homeostasis.

The process of Active Transport requires the use
of energy (in the cell the energy molecule is
called ATP)
33
Active Transport

Active Transport: Movement of materials
against (or UP) a concentration gradient.
“Activity takes energy!!”
35
Active Transport: Proteins
Carrier Protein: Binds with a particle to be
transported during Active Transport and
has a shape that fits a specific molecule or
Ion! (Atom with a charge!!!)
 Changes shape so that the particle can be
moved and released on other side of
membrane!!

36
Carrier Proteins!!!
ATP
37
Membrane Proteins
Done
Channel Proteins (Passive Transport)
Done
 Carrier Proteins (Active Transport)
 Marker Proteins (Identification)
Next Slide (#38)
 Receptor Proteins (Information)
Two Slides Away (#39)

38
Marker Proteins

Identifies this cell as belonging to YOU!!!
A Blood
B Blood
AB Blood
O Blood
Why is it important that you are matched before receiving blood??
39
Receptor Proteins

Allows Information to enter the cell!!
Causes a change inside the cell!!
Ex. Hormones!!!
40
Cell Transport Processes

Because of the cell membrane’s unique
characteristics (Fluid Mosaic, Semipermeable, Selectively permeable) the
cell has several other options for intake
and export of molecules:
1. Exocytosis
2.
Endocytosis
41
EXocytosis
Exocytosis: The expulsion or secretion of
materials from a cell. (Get rid of it!!!)
 EXocytosis = EXit!!!

42
ENdocytosis
Endocytosis: Process by which a cell
surrounds and takes “in” material from its
environment.
 ENdocytosis = ENter

43
______________
____________
____________
44
Cell Size Limitations



1.
2.
Diffusion; Slow with distance!!!
DNA: Not enough to support protein needs
Cell’s Surface Area to Volume:
As a cell’s size increases, its volume increases much
faster than its surface area…and yet a bigger cell
would require more imports and exports!!!
Surface area is needed for
the exchange of molecules
(Chemical Reactions)
45
The Final Product
The “Cell Membrane”
46
How do these membrane proteins
relate to larger concepts in
organisms??
1.
2.
3.
Circulatory System/ Respiratory System: Your
cells use Facilitated transport methods to help
maintain homeostasis; Example: Oxygen &
Carbon Dioxide
Nervous System :Nerve cells use Receptor
Proteins to communicate information
Immune system :White blood cells engulfing
foreign bodies by blood typing use Marker
Proteins
47
“Marshmallow Activity”

In this activity you and your group will construct a 2
dimensional (flat) cell membrane with the materials I
have supplied and/or anything that you may have!
Make sure to include:
1. An accurate simulation of the “Fluid Mosaic” model
2.
How the cell goes thru passive and active transport
3.
All 4 of the membrane proteins discussed in notes
48
EOC Practice Problems

In humans, glucose is
kept in balance in the
bloodstream by insulin.
Which concept does this
best illustrate?
A. Adaptation
B. Homeostasis
C. Metabolism
D. Organization

Which cell process will
move substances against
a concentration gradient?
A. diffusion
B. facilitated diffusion
C. osmosis
D. active transport
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