Cell Membrane_Revised.ppt
Cell Membrane
Notes
About Cell Membranes
• All cells have a cell
membrane
• Functions:
a.Controls what enters and
exits the cell to maintain
an internal balance
called homeostasis
b.Provides protection and
support for the cell
About Cell Membranes
• The cell membrane is
constantly moving
• Proteins, and other
structures move about
the cell membrane (like a
fluid)
What is the purpose of cellular
transport?
• The cell membrane regulates the
passage of materials into and out of
the cell
– Needed materials move in
• Glucose, oxygen, amino acids, etc.
– Excess materials move out
• Carbon dioxide, digested materials,
etc.
Membrane
movemen
t animat
ion
How?
• A cell membrane is semipermeable
(selectively permeable), meaning that some
substances can pass directly through the
cell membrane while other substances
cannot.
• Materials can enter or exit through the cell
membrane
by passive
transport
or active
So what needs
to get across
the membrane?
transport.
sugar
lipids
aa
O2
H2O
salt
waste
Types of Cellular
Transport
•
Weeee!
!!
Passive Transport
*cell does not use energy
1. Diffusion
2. Facilitated Diffusion
3. Osmosis
•
•Animations of
Active Transport &
Passive Transport
hig
h
low
Active Transport
*cell does use energy
1. Protein Pumps
2. Endocytosis
3. Exocytosis
This is
gonna
be
hard
work!!
hig
h
low
Passive Transport
•
•
•
cell uses no energy
molecules move randomly
The random motion of molecules
occurs along the concentration
gradient meaning molecules
spread out from an area of high
concentration to an area of low
concentration.
• (HighLow)
•
Three types:
3 Types of Passive
Transport
1. Diffusion – is the spreading out of
molecules across a cell membrane
until they are equally concentrated.
2. Facilitative Diffusion – diffusion
with the help of transport proteins
3. Osmosis – diffusion of water
Passive Transport:
1. Diffusion
•
Diffusion: random movement of particles
from an area of high concentration to
an area of low concentration.
•
Diffusion continues until all molecules are
evenly spaced (equilibrium is reached)
•
Note: molecules will still move around but
stay spread out.
assive Transport:
1. Diffusion
fat
inside cell
fat
fat
LOW
Simple Diffu
sion Animati
on
fat
fat
fat
HIGH
outside cell
fat
fat
fat
fat
fat
fat
fat
Passive Transport:
. Facilitated Diffusion
Facilitated diffusion:
•diffusion of specific particles from high to low
concentration
•Help from transport proteins found in the
membrane
HIGH
Glucose is an example of a
molecule that is transported
through proteins
LOW
Passive Transport:
2. Facilitated Diffusion
sugar
inside cell
sugar
sugar
sugar
sugar
• Channel Protei
ns
animations
sugar
LOW
HIGH
outside cell
sugar
sugar
sugar
sugar
sugar
sugar
Passive Transport:
3. Osmosis
• Osmosis: diffusion of
water through a
selectively permeable
membrane
• Water moves from a high
concentration of water
to a low concentration of
water
• More on this soon***
Osmosis
animation
Active Transport
• Requires the cell to use energy
• Actively moves molecules to where
they are needed
• Molecules move against the
concentration gradient - from an area
of low concentration to an area of
high concentration
• (Low High)
• Three Types:
Types of Active
Transport
Sodium Potassi
um Pumps
(Active
Transport using
proteins)
1. Protein Pumps transport proteins
that require energy
to do work
Protein
changes shape
to move
molecules: this
requires
Types of Active Transport
2. Endocytosis: taking
bulky material into a cell by
forming a vesicle
• Uses energy
• Cell membrane infolds around food
particle
• “cell eating”
• forms food vacuole &
digests food
• This is how white blood
cells eat bacteria!
Endocytosis & E
xocytosis
animations
Types of Active Transport
3. Exocytosis: Forces
material out of cell in
bulk
• Membrane surrounding
the material fuses with
cell membrane
• Cell changes shape –
requires energy
• Ex: Hormones or
wastes released from
cell
Revisited:
Passive Transport:
Osmosis
• Osmosis: diffusion of
water through a selectively
permeable membrane
• Water moves from a high
concentration of water to a
low concentration of water
• Because water is so small
and in such abundance,
the cell cannot control its
movement through the cell
membrane.
Osmosis
animation
Effects of Osmosis on Life
• Water moves freely
through through pores
(blue and white molecules)
• Solute (green) too large
to move across.
• Reminder:
–Solute: what is being dissolved
–Solvent: what dissolves the solute
• In salt water, the solute is the salt and the
solvent is the water
Hypotonic Solution
• Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic
solutions
Hypotonic: The solution has a lower
concentration of solutes and a higher
concentration of water than inside the cell.
(Low solute; High water)
Result: Water moves from the solution to
inside the cell): Cell Swells and bursts open
(lyse)!
Hypertonic Solution
• Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic
solutions
Hypertonic: The solution has a higher
concentration of solutes and a lower
concentration of water than inside the cell.
(High solute; Low water)
shrink
s
Result: Water moves out of the cell into the
solution:
Cell shrivels!
Isotonic Solution
• Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic
solutions
Isotonic: The concentration of solutes in the
solution is equal to the concentration of
solutes inside the cell.
Result: Water moves equally in both
directions and the cell remains same size!
In what type of solution are these
cells?
A
B
Hyperto
nic
Isoton
ic
C
Hypotoni
c
Cell Membrane
Notes
About Cell Membranes
• All cells have a _____
__________________
• Functions:
a.Controls what enters
and exits the cell to
maintain an internal
balance called
_________________
b.Provides protection
and support for the cell
About Cell Membranes
• The cell membrane is constantly
_______________
• Proteins, and other structures move
about the cell membrane (like a
__________)
What is the purpose of cellular
transport?
• The cell membrane regulates the
passage of materials __________ and
_______ of the cell
– Needed materials move _____
• Glucose, oxygen, amino acids, etc.
– Excess materials move _______
• Carbon dioxide, digested materials,
etc.
Membrane
movemen
t animat
ion
How?
• A cell membrane is _____________________
(selectively permeable), meaning that
__________ substances can pass directly
through the cell membrane while other
substances ___________
• Materials can enter or exit through the cell
membrane by __________ transport or
_________
So what transport.
needs to get across the membrane?
sugar
lipids
aa
O2
H2O
salt
waste
Types of Cellular
Transport
•
Passive Transport
*cell does ______ use energy
1. _______________
2. Facilitated Diffusion
3. ______________
•
•Animations of
Active Transport &
Passive Transport
Active Transport
*cell does use _________
1. Protein Pumps
2. Endocytosis
3. _______________
Weeee!
!!
hig
h
low
This is
gonna
be
hard
work!!
hig
h
low
Passive Transport
•
•
•
cell uses no energy
molecules move __________________
The random motion of molecules
occurs along the concentration
gradient meaning molecules spread
out from an area of _________
concentration to an area of
__________ concentration.
• (HighLow)
• Three types:
3 Types of Passive
Transport
1. Diffusion – is the spreading out of
molecules across a cell membrane
until they are equally concentrated.
2. Facilitative Diffusion – diffusion
with the help of _______________
_______________
3. Osmosis – diffusion of ___________
Passive Transport:
1. Diffusion
•
Diffusion: ____________ movement of
particles from an area of high
concentration to an area of low
concentration.
•
Diffusion continues until all molecules are
evenly spaced (___________________ is
reached)
•
Note: molecules will still ____________
around but stay spread out.
assive Transport:
1. Diffusion
fat
inside cell
fat
fat
LOW
Simple Diffu
sion Animati
on
fat
fat
fat
HIGH
outside cell
fat
fat
fat
fat
fat
fat
fat
Passive Transport:
. Facilitated Diffusion
Facilitated diffusion:
•diffusion of specific particles from high to low
concentration
•Help from _____________ ______________found
in the membrane
•These molecules cannot pass through the
membrane alone
HIGH
Glucose is an example of a
molecule that is transported
through proteins
LOW
Passive Transport:
2. Facilitated Diffusion
sugar
inside cell
sugar
sugar
sugar
sugar
• Channel Protei
ns
animations
sugar
LOW
HIGH
outside cell
sugar
sugar
sugar
sugar
sugar
sugar
Passive Transport:
3. Osmosis
• Osmosis: diffusion of
_____________ through a
selectively permeable
membrane
• Water moves from a
_________ concentration of
water to a __________
concentration of water
• More on this soon***
Osmosis
animation
Active Transport
• Requires the cell to use ________________
• Actively moves molecules to where
they are needed
• Molecules move against the
concentration gradient - from an area
of __________ concentration to an
area of __________ concentration
• (Low High)
• Three Types:
Types of Active
Transport
Sodium
Potassium
Pumps (Active
Transport using
proteins)
1. ____________ Pumps
-transport proteins
that require energy to
do work
Protein
changes shape
to move
molecules: this
requires
Types of Active Transport
2. __________________: taking
bulky material into a cell by
forming a vesicle
• Uses energy
• Cell membrane in-folds
around food particle
• “_____________________”
• forms food vacuole &
digests food
• This is how white blood
cells eat bacteria!
Endocytosis &
Exocytosis
animations
Types of Active Transport
3. Exocytosis: Forces
material out of cell in
bulk
• Membrane surrounding
the material ____________
with cell membrane
• Cell changes shape –
requires energy
• Ex: Hormones or
wastes released from
cell
Revisited:
Passive Transport:
Osmosis
• Osmosis: diffusion of water
through a selectively
permeable membrane
• Water moves from a high
concentration of water to a
low concentration of water
• Because water is
so___________and in such
abundance, the cell
__________control its
movement through the cell
membrane.
Osmosis
animation
Revisited:
Passive Transport:
Osmosis
• Osmosis: diffusion of
water through a selectively
permeable membrane
• Water moves from a high
concentration of water to a
low concentration of water
• Because water is so small
and in such abundance,
the cell cannot control its
movement through the cell
membrane.
Osmosis
animation
Effects of Osmosis on Life
• Water moves_________
through pores
(blue and white molecules)
• Solute (green) too __________
to move across.
• Reminder:
–Solute: what is being dissolved
–Solvent: what dissolves the solute
• In salt water, the solute is the salt and the
solvent is the water
Hypotonic Solution
• Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic
solutions
Hypotonic: The solution has a ____________
concentration of solutes and a higher
concentration of water than inside the cell.
(Low solute; High water)
Result: Water moves from the solution to
___________ the cell): Cell ____________ and
bursts open (lyse)!
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 solute; Low water)
shrink
s
Result: Water moves ___________the cell into
the solution:
Cell
_____________!
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 _____________ in both
directions and the cell remains same size!
In what type of solution are these
cells?
A
_____________
B
C
_____________ _____________
How Organisms Deal with
Osmotic Pressure
•
Paramecium
(protist)
removing
excess water
video
• Bacteria and plants have cell walls that
prevent them from over-expanding. In plants the
pressure exerted on the cell wall is called turgor
pressure.
• A protist like the paramecium has contractile
vacuoles that collect water flowing in and pump
it out to prevent them from over-expanding.
• Salt water fish pump salt out of their
specialized gills so they do not dehydrate.
• Animal cells are bathed in blood. Kidneys
keep the blood isotonic by remove excess salt
and water.
Notes
About Cell Membranes
• All cells have a cell
membrane
• Functions:
a.Controls what enters and
exits the cell to maintain
an internal balance
called homeostasis
b.Provides protection and
support for the cell
About Cell Membranes
• The cell membrane is
constantly moving
• Proteins, and other
structures move about
the cell membrane (like a
fluid)
What is the purpose of cellular
transport?
• The cell membrane regulates the
passage of materials into and out of
the cell
– Needed materials move in
• Glucose, oxygen, amino acids, etc.
– Excess materials move out
• Carbon dioxide, digested materials,
etc.
Membrane
movemen
t animat
ion
How?
• A cell membrane is semipermeable
(selectively permeable), meaning that some
substances can pass directly through the
cell membrane while other substances
cannot.
• Materials can enter or exit through the cell
membrane
by passive
transport
or active
So what needs
to get across
the membrane?
transport.
sugar
lipids
aa
O2
H2O
salt
waste
Types of Cellular
Transport
•
Weeee!
!!
Passive Transport
*cell does not use energy
1. Diffusion
2. Facilitated Diffusion
3. Osmosis
•
•Animations of
Active Transport &
Passive Transport
hig
h
low
Active Transport
*cell does use energy
1. Protein Pumps
2. Endocytosis
3. Exocytosis
This is
gonna
be
hard
work!!
hig
h
low
Passive Transport
•
•
•
cell uses no energy
molecules move randomly
The random motion of molecules
occurs along the concentration
gradient meaning molecules
spread out from an area of high
concentration to an area of low
concentration.
• (HighLow)
•
Three types:
3 Types of Passive
Transport
1. Diffusion – is the spreading out of
molecules across a cell membrane
until they are equally concentrated.
2. Facilitative Diffusion – diffusion
with the help of transport proteins
3. Osmosis – diffusion of water
Passive Transport:
1. Diffusion
•
Diffusion: random movement of particles
from an area of high concentration to
an area of low concentration.
•
Diffusion continues until all molecules are
evenly spaced (equilibrium is reached)
•
Note: molecules will still move around but
stay spread out.
assive Transport:
1. Diffusion
fat
inside cell
fat
fat
LOW
Simple Diffu
sion Animati
on
fat
fat
fat
HIGH
outside cell
fat
fat
fat
fat
fat
fat
fat
Passive Transport:
. Facilitated Diffusion
Facilitated diffusion:
•diffusion of specific particles from high to low
concentration
•Help from transport proteins found in the
membrane
HIGH
Glucose is an example of a
molecule that is transported
through proteins
LOW
Passive Transport:
2. Facilitated Diffusion
sugar
inside cell
sugar
sugar
sugar
sugar
• Channel Protei
ns
animations
sugar
LOW
HIGH
outside cell
sugar
sugar
sugar
sugar
sugar
sugar
Passive Transport:
3. Osmosis
• Osmosis: diffusion of
water through a
selectively permeable
membrane
• Water moves from a high
concentration of water
to a low concentration of
water
Osmosis
animation
Active Transport
• Requires the cell to use energy
• Actively moves molecules to where
they are needed
• Molecules move against the
concentration gradient - from an area
of low concentration to an area of
high concentration
• (Low High)
• Three Types:
Types of Active
Transport
Sodium Potassi
um Pumps
(Active
Transport using
proteins)
1. Protein Pumps transport proteins
that require energy
to do work
Protein
changes shape
to move
molecules: this
requires
Types of Active Transport
2. Endocytosis: taking
bulky material into a cell by
forming a vesicle
• Uses energy
• Cell membrane infolds around food
particle
• “cell eating”
• forms food vacuole &
digests food
• This is how white blood
cells eat bacteria!
Endocytosis & E
xocytosis
animations
Types of Active Transport
3. Exocytosis: Forces
material out of cell in
bulk
• Membrane surrounding
the material fuses with
cell membrane
• Cell changes shape –
requires energy
• Ex: Hormones or
wastes released from
cell
Revisited:
Passive Transport:
Osmosis
• Osmosis: diffusion of
water through a selectively
permeable membrane
• Water moves from a high
concentration of water to a
low concentration of water
• Because water is so small
and in such abundance,
the cell cannot control its
movement through the cell
membrane.
Osmosis
animation
Effects of Osmosis on Life
• Water moves freely
through through pores
(blue and white molecules)
• Solute (green) too large
to move across.
• Reminder:
–Solute: what is being dissolved
–Solvent: what dissolves the solute
• In salt water, the solute is the salt and the
solvent is the water
Hypotonic Solution
• Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic
solutions
Hypotonic: The solution has a lower
concentration of solutes and a higher
concentration of water than inside the cell.
(Low solute; High water)
Result: Water moves from the solution to
inside the cell): Cell Swells and bursts open
(lyse)!
Hypertonic Solution
• Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic
solutions
Hypertonic: The solution has a higher
concentration of solutes and a lower
concentration of water than inside the cell.
(High solute; Low water)
shrink
s
Result: Water moves out of the cell into the
solution:
Cell shrivels!
Isotonic Solution
• Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic
solutions
Isotonic: The concentration of solutes in the
solution is equal to the concentration of
solutes inside the cell.
Result: Water moves equally in both
directions and the cell remains same size!
In what type of solution are these
cells?
A
B
Hyperto
nic
Isoton
ic
C
Hypotoni
c
Cell Membrane
Notes
About Cell Membranes
• All cells have a _____
__________________
• Functions:
a.Controls what enters
and exits the cell to
maintain an internal
balance called
_________________
b.Provides protection
and support for the cell
About Cell Membranes
• The cell membrane is constantly
_______________
• Proteins, and other structures move
about the cell membrane (like a
__________)
What is the purpose of cellular
transport?
• The cell membrane regulates the
passage of materials __________ and
_______ of the cell
– Needed materials move _____
• Glucose, oxygen, amino acids, etc.
– Excess materials move _______
• Carbon dioxide, digested materials,
etc.
Membrane
movemen
t animat
ion
How?
• A cell membrane is _____________________
(selectively permeable), meaning that
__________ substances can pass directly
through the cell membrane while other
substances ___________
• Materials can enter or exit through the cell
membrane by __________ transport or
_________
So what transport.
needs to get across the membrane?
sugar
lipids
aa
O2
H2O
salt
waste
Types of Cellular
Transport
•
Passive Transport
*cell does ______ use energy
1. _______________
2. Facilitated Diffusion
3. ______________
•
•Animations of
Active Transport &
Passive Transport
Active Transport
*cell does use _________
1. Protein Pumps
2. Endocytosis
3. _______________
Weeee!
!!
hig
h
low
This is
gonna
be
hard
work!!
hig
h
low
Passive Transport
•
•
•
cell uses no energy
molecules move __________________
The random motion of molecules
occurs along the concentration
gradient meaning molecules spread
out from an area of _________
concentration to an area of
__________ concentration.
• (HighLow)
• Three types:
3 Types of Passive
Transport
1. Diffusion – is the spreading out of
molecules across a cell membrane
until they are equally concentrated.
2. Facilitative Diffusion – diffusion
with the help of _______________
_______________
3. Osmosis – diffusion of ___________
Passive Transport:
1. Diffusion
•
Diffusion: ____________ movement of
particles from an area of high
concentration to an area of low
concentration.
•
Diffusion continues until all molecules are
evenly spaced (___________________ is
reached)
•
Note: molecules will still ____________
around but stay spread out.
assive Transport:
1. Diffusion
fat
inside cell
fat
fat
LOW
Simple Diffu
sion Animati
on
fat
fat
fat
HIGH
outside cell
fat
fat
fat
fat
fat
fat
fat
Passive Transport:
. Facilitated Diffusion
Facilitated diffusion:
•diffusion of specific particles from high to low
concentration
•Help from _____________ ______________found
in the membrane
•These molecules cannot pass through the
membrane alone
HIGH
Glucose is an example of a
molecule that is transported
through proteins
LOW
Passive Transport:
2. Facilitated Diffusion
sugar
inside cell
sugar
sugar
sugar
sugar
• Channel Protei
ns
animations
sugar
LOW
HIGH
outside cell
sugar
sugar
sugar
sugar
sugar
sugar
Passive Transport:
3. Osmosis
• Osmosis: diffusion of
_____________ through a
selectively permeable
membrane
• Water moves from a
_________ concentration of
water to a __________
concentration of water
Osmosis
animation
Active Transport
• Requires the cell to use ________________
• Actively moves molecules to where
they are needed
• Molecules move against the
concentration gradient - from an area
of __________ concentration to an
area of __________ concentration
• (Low High)
• Three Types:
Types of Active
Transport
Sodium
Potassium
Pumps (Active
Transport using
proteins)
1. ____________ Pumps
-transport proteins
that require energy to
do work
Protein
changes shape
to move
molecules: this
requires
Types of Active Transport
2. __________________: taking
bulky material into a cell by
forming a vesicle
• Uses energy
• Cell membrane in-folds
around food particle
• “_____________________”
• forms food vacuole &
digests food
• This is how white blood
cells eat bacteria!
Endocytosis &
Exocytosis
animations
Types of Active Transport
3. Exocytosis: Forces
material out of cell in
bulk
• Membrane surrounding
the material ____________
with cell membrane
• Cell changes shape –
requires energy
• Ex: Hormones or
wastes released from
cell
Revisited:
Passive Transport:
Osmosis
• Osmosis: diffusion of water
through a selectively
permeable membrane
• Water moves from a high
concentration of water to a
low concentration of water
• Because water is
so___________and in such
abundance, the cell
__________control its
movement through the cell
membrane.
Osmosis
animation
Revisited:
Passive Transport:
Osmosis
• Osmosis: diffusion of
water through a selectively
permeable membrane
• Water moves from a high
concentration of water to a
low concentration of water
• Because water is so small
and in such abundance,
the cell cannot control its
movement through the cell
membrane.
Osmosis
animation
Effects of Osmosis on Life
• Water moves_________
through pores
(blue and white molecules)
• Solute (green) too __________
to move across.
• Reminder:
–Solute: what is being dissolved
–Solvent: what dissolves the solute
• In salt water, the solute is the salt and the
solvent is the water
Hypotonic Solution
• Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic
solutions
Hypotonic: The solution has a ____________
concentration of solutes and a higher
concentration of water than inside the cell.
(Low solute; High water)
Result: Water moves from the solution to
___________ the cell): Cell ____________ and
bursts open (lyse)!
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 solute; Low water)
shrink
s
Result: Water moves ___________the cell into
the solution:
Cell
_____________!
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 _____________ in both
directions and the cell remains same size!
In what type of solution are these
cells?
A
_____________
B
C
_____________ _____________
How Organisms Deal with
Osmotic Pressure
•
Paramecium
(protist)
removing
excess water
video
• Bacteria and plants have cell walls that
prevent them from over-expanding. In plants the
pressure exerted on the cell wall is called turgor
pressure.
• A protist like the paramecium has contractile
vacuoles that collect water flowing in and pump
it out to prevent them from over-expanding.
• Salt water fish pump salt out of their
specialized gills so they do not dehydrate.
• Animal cells are bathed in blood. Kidneys
keep the blood isotonic by remove excess salt
and water.