Download Structure of the Cell Membrane

Cellular Transport
Notes
About Cell Membranes
1.All cells have a _____
_________
2.Functions:
a.Controls what enters
and exits the cell ___
_________________
called ____________
b.Provides _________
and _______ for the cell
TEM picture of a
real cell membrane.
About Cell Membranes (continued)
3.Structure of cell membrane
Lipid Bilayer -2 layers of
_____________
a.Phosphate head is _____
(________ - water loving)
b.Fatty acid tails ________
(__________ - water
fearing)
c._________ embedded in
membrane
Phospholipid
Lipid Bilayer
Polar heads _____________
love water
______of the
& dissolve. cell membrane
Non-polar
tails hide
from water.
Carbohydrate cell
markers
Proteins
Membrane
movement
animation
About Cell Membranes (continued)
• 4. Cell membranes have ______(holes) in it
a.____________ ___________: Allows some
molecules in and keeps other molecules out
b.The ___________ helps it be selective!
Pores
Structure of the Cell Membrane
Outside of cell
Proteins
Lipid
Bilayer
Transport
Protein
Animations
of membrane
Go to structure
Section:
Carbohydrate
chains
Phospholipids
Inside of cell
(cytoplasm)
Types of Cellular Transport
•Animations of Active
Transport & Passive
Transport
•
Weeee!!
!
Passive Transport
cell ________ use energy
1. _________
2. _________ _________
3. _________
•
high
low
Active Transport
cell ____ use energy
1. _______ ________
2. ___________
3. ___________
This is
gonna
be hard
work!!
high
low
Passive Transport
•
•
•
cell _____ ___ _________
molecules move __________
Molecules spread out from an area of
_____ concentration to an area of
_____concentration.
• (HighLow)
•
Three types. . .
3 Types of Passive Transport
1. Diffusion
2. Facilitative Diffusion – diffusion with
the help of _________ _________
3. Osmosis – diffusion __ _______
Passive Transport:
1. Diffusion
Simple Diffusion
Animation
1. Diffusion: ______ movement
of particles from an area of
______ concentration to an
area of ____ concentration.
(High to Low)
•
Diffusion continues until all
molecules are _____ _______
(__________ is reached)-Note:
molecules will still _____ ______
but stay spread out.
http://bio.winona.edu/berg/Free.htm
Passive Transport:
2. Facilitated Diffusion A
2. Facilitated diffusion:
diffusion of specific particles
______ _______ ________
found in the _________
a.Transport Proteins are
________ – they “select”
only certain molecules
to cross the membrane
b.Transports _______ or
________ molecules
Facilitated
diffusion
(Channel
Protein)
Carrier Protein
B
Diffusion
(Lipid
Bilayer)
Passive Transport: 2. Facilitated Diffusion
Glucose
molecules
Cellular Transport From aHigh Concentration
High
• Channel Proteins
animations
Cell Membrane
Low Concentration
Through a 
Go to
Section:
Transport
Protein
Protein
channel
Low
Passive Transport:
3. Osmosis
• 3.Osmosis: diffusion of
_______ through a
selectively permeable
membrane
• Water moves from
_____ to ____
concentrations
Osmosis
animation
•Water moves freely
through pores.
•Solute (green) too
large to move across.
Effects of Osmosis on Life
• Osmosis- diffusion of water through a
selectively permeable membrane
• Water is so small and there is so much
of it the cell can’t control it’s movement
through the cell membrane.
•
Hypertonic Solution
Osmosis
Animations for
isotonic, hypertonic,
and hypotonic
solutions
Hypertonic: The solution has a ______ concentration
of solutes and a ______ concentration of water than
inside the cell. (High _______; Low _______)
shrinks
Result: Water moves from ______ the cell _____ the
solution: Cell shrinks (______________)!
•
Hypotonic Solution
Osmosis
Animations for
isotonic, hypertonic,
and hypotonic
solutions
Hypotonic: The solution has a _____ concentration of
solutes and a ______ concentration of water than
inside the cell. (Low ______; High _______)
Result: Water moves _____ the solution __ ______the
cell): Cell _______ and _____ _____ (cytolysis)!
•
Isotonic Solution
Osmosis
Animations for
isotonic, hypertonic,
and hypotonic
solutions
Isotonic: The concentration of solutes in the solution
is _____ to the concentration of solutes inside the cell.
Result: Water moves equally in ____ __________and
the cell _____ _______ _____! (Dynamic Equilibrium)
What type of solution are these cells in?
A
_________
B
________
C
_________
How Organisms Deal
with Osmotic Pressure
•Bacteria and plants have ____ _____ that prevent them
from over-expanding. In plants the pressure exerted on
the cell wall is called ____ _________.
•A protist like paramecium has _______ _________that
collect water flowing in and pump it out to prevent them
from over-expanding.
http://www.linkpublishing.com/video-transport.htm#Osmosis_-_Red_Onion
•Salt water fish pump salt out of their specialized ___ so
they do not dehydrate.
•Animal cells are bathed in ______. Kidneys keep the
blood _________ by removing excess salt and water.
•Active Transport
• Cell _____/______ energy
• Energy (___) is released in the mitochondria
• Actively ______ molecules to where they are
needed
• Movement from an area of ___ concentration
to an area of ____ concentration (materials
move __/________ the concentration gradient)
• (Low
 High)
• Three Types . . .
Types of Active Transport
1. Protein Pumps –
________/_____ proteins
that require energy to do
work.
Each carrier protein is
________.
Ie: it can only transport
the solute particle that __
into the shape of the
carrier protein’s ______
site.
Protein changes
shape to move
molecules: this
requires energy!
Types of Active Transport
Sodium
Potassium Pumps
(Active Transport
using proteins)
Protein Pump Examples:
a) Calcium Pumps – transport Ca+2
____ ___ a cell
b) Sodium / Potassium Pumps - are
important in nerve responses and
transport Na+ ___ and K+ ___ a cell
http://course1.winona.edu/sberg/ANIMTNS/Na-Kpump.htm
Types of Active Transport
2. Endocytosis: taking _____ material ____ a cell
•
•
•
•
Uses energy
Cell membrane in-folds around ____ ________
“cell eating”
Forms food ________ & enzymes from
lysosomes ________ food
Types of Active Transport
2 Types of Endocytosis:
i) Phagocytosis – used to
absorb _____ particles.
ie: ________ “eating”
ciliates
&
____ ____ ____
“eating”
viruses/microbes
Types of Active Transport
ii) Pinocytosis – used
to absorb ______
________
ie: Intestine cells
absorbing fat
Types of Active Transport
3. Exocytosis: Forces material
____ ____cell in bulk
• Membrane surrounding the
material (vacuole formed
from golgi apparatus) fuses
with cell membrane
http://www.mhhe.com/biosci/genbio/elearning/raven6/resources06.mhtml
• Cell changes ______
– requires energy
ie: Hormones or wastes
released from cell
Endocytosis &
Exocytosis
animations
Types of Active Transport
Cytoplasmic Streaming
– Cytoplasm _____
_______ around inside
the cell
- Requires ______ from
the cell
- Probably uses
____________ of protein
in the cytoplasm
http://www.youtube.com/wat
ch?v=wEK9EdvDz2w