Journal 12/17
Procedure:
1.
Turn in assignments to bin
2.
Get out journal sheet
3.
Get out notes on passive
transport
4.
Begin journal
Quiet while you do this!
Assignments Due:
• Active transport HW
DUE Today
• Exam studyguide DUE
tomorrow 12/18
• Exam: Homeostasis
and transport 12/18
In 25 words,
1. Describe the 5 ways cells can
transport materials across the plasma
membrane.
2. Classify each as active or passive
transport
Journal 12/18
Procedure:
1.
Turn in assignments to bin
2.
Get out journal sheet
3.
Get out notes on passive
transport
4.
Begin journal
Quiet while you do this!
Assignments Due:
• Exam studyguide DUE
today
• Exam: Homeostasis
and transport TODAY
In 25 words,
1. Differentiate between osmosis,
simple diffusion, and facilitated
diffusion.
2. Differentiate between protein pumps
and vesicle transport.
Journal 12/14
Procedure:
1.
Turn in assignments to bin
2.
Get out journal sheet
3.
Get out notes on passive
transport
4.
Begin journal
Quiet while you do this!
Assignments Due:
• Active transport HW
DUE Monday
• Exam: Homeostasis
and transport 12/18
In 25 words,
1. What are the two types of active
transport?
2. Describe each type.
Journal 12/13
Procedure:
1.
Turn in assignments to bin
2.
Get out journal sheet
3.
Get out notes on passive
transport
4.
Begin journal
Quiet while you do this!
Assignments Due:
• Passive transport
review skill sheet DUE
TODAY
• Exam: Homeostasis
and transport 12/18
In 25 words,
1. How is facilitated diffusion different
from simple diffusion?
2. How is osmosis different from simple
diffusion?
Journal 12/12
Procedure:
1.
Turn in assignments to bin
2.
Get out journal sheet
3.
Get out notes on passive
transport
4.
Begin journal
Quiet while you do this!
Assignments Due:
• Stem cell research paper DUE
TODAY!
• Passive transport review skill sheet
DUE Thurs. 12/13 (you did this with
the sub yesterday)
Quiz: Passive Transport 12/13 (Thurs)
In 25 words,
1. What are the three types of passive
transport?
2. Give a description of each.
Journal 12/11
Week 16
Procedure:
1.
Turn in assignments to bin
2.
Get make-up work from bin
3.
Get out journal sheet
4.
Get out notes on passive transport
5.
Begin journal
Quiet while you do this!
Assignments Due:
• Stem cell research paper
DUE 12/12 (Wed)
• Passive transport review
skill sheet DUE Thurs.
12/13 (you did this with
the sub yesterday)
Quiz: Passive Transport
12/13 (Thurs)
In 25 words,
1. What is the difference between
passive and active transport?
2. Define osmosis.
3. What is facilitated diffusion?
Journal 12/7
Assignments Due:
• Stem cell research paper DUE 12/12
(Wed)
• Cell organelle remediation packet
DUE TODAY
Quiz: Passive Transport 12/13 (Thurs)
In 25 words,
1. Give a brief description of what
happened yesterday in Osmosis
Jones.
2. What type of cell is Osmosis Jones?
Agenda:
We are watching Osmosis Jones!
Journal 12/6
Assignments Due:
• Stem cell research paper DUE 12/12
(Wed)
• Cell organelle remediation packet
DUE 12/7 (Fri)
• Passive transport reading DUE 12/6
TODAY
• Quiz: Passive Transport 12/13
(Thurs)
In 25 words,
1. What is osmosis?
2. What is the difference between
hypertonic, hypotonic, and isotonic?
Agenda:
We are watching Osmosis Jones!
Journal 12/5
Assignments Due:
• Stem cell research paper DUE 12/12
(Wed)
• Cell organelle remediation packet
DUE 12/7 (Fri)
• Passive transport reading DUE 12/6
(Thurs)
In 25 words,
1.What is the difference between passive
and active transport?
2. What drives diffusion?
Agenda
1.
Finish notes
2.
Short video review of passive transport
Journal 12/4
Assignments Due:
• Stem cell research paper DUE 12/12
(Wed)
• Cell organelle remediation packet
DUE 12/7 (Fri)
• Passive transport reading DUE 12/6
(Thus)
In 25 words,
1.What organelle controls what
substances enter and leave the cell?
2.What materials make up the plasma
membrane?
Chapter 5
Homeostasis & Cell Transport
VIDEO
lab
VIDEO
Here a White Blood Cell eats some bacteria.
How does the bacteria get into the cell?
http://www.youtube.com/watch?v=fpOxgAU5fFQ
5-1 Passive Transport Objectives




Explain how an equilibrium is established
as a result of diffusion
Distinguish between diffusion and osmosis
Explain how substances cross the cell
membrane through facilitated diffusion
Explain how ion channels assist the
diffusion of ions across the cell membrane
Homeostasis


The ability or tendency of an organism
or cell to maintain internal equilibrium
by adjusting its physiological processes
Cell membranes help organisms
maintain homeostasis by controlling
what substances may enter or leave
cells
Why cells need to maintain homeostasis:


Cells need to be able to be different than their
environment
Maintaining pH, water concentration, types of
molecules, etc.
Structure of
cell membrane:
Quiz Question!!
What three
macromolecules
make up a cell
membrane?
• Phospholipids
• Proteins
• Carbohydrates

The Cell Membrane is
SEMIPERMEABLE



ONLY ALLOWS CERTAIN
MOLECULES TO PASS
THROUGH
Small molecules like WATER,
OXYGEN, AND CARBON
DIOXIDE can move in and
out freely
Large molecules like
PROTEINS &
CARBOHYDRATES CANNOT
What is Equilibrium?



A state that exists when the concentration of a
substance is the same throughout a space
A condition in which all acting influences are
canceled by others, resulting in a stable,
balanced, or unchanging system
Reached when molecules are of the same
concentration, though they keep moving
5 basic ways things get into
or out of cells
1.
2.
3.
4.
5.
Simple Diffusion
Osmosis
Facilitated Diffusion
Cell Membrane Pumps
Vesicles
passive transport(1-3) active transport (4-5)
Passive Transport

Some substances can cross the cell membrane
without any input of Energy by the
cell. The movement of such substances across the
membrane is known as PASSIVE TRANSPORT
 1.
Simple Diffusion
 2. Osmosis
 3. Facilitated Diffusion
1. Simple Diffusion
• The movement of molecules from an
area of high concentration to an area of
low concentration
CONCENTRATION GRADIENT
-The difference in concentrations
of molecules across a space
Kinetic Energy of molecules
Kinetic energy is energy of motion

Molecules are in Constant Motion


Molecules move in a straight line unless
they hit something
If no object blocks their path they keep
moving-so- they move to where there are
less molecules

Diffusion occurs when molecules move
randomly away from each other

Diffusion is driven entirely by kinetic
energy
Simple Diffusion across a membrane



Few substances can diffuse directly through
the lipid bilayer of the membrane
The only substances that can do this are lipidsoluble molecules (steroids, -or very small
molecules, such as H2O, O2 and CO2)
Since no energy is added -substances can only
move down their concentration gradient
2. Osmosis -the movement of water
molecules from an area of high concentration
to an area of low concentration.
Osmosis

the diffusion of water across a membrane

Same as regular diffusion, but water is so
important it has its own name - osmosis.

Water molecules can diffuse freely across a
membrane, but always down a
concentration gradient – so water
diffuses from a dilute to a concentrated
solution
video
rap
Types of solutions

There are three possible concentrations of solution
to consider:
 Isotonic
solution a solution of
equal concentration of solutes to a cell
 Hypertonic
solution a solution of
higher concentration of solutes than a cell
 Hypotonic
solution a solution of
lower concentration of solutes than a cell
Water moves freely across the cell membrane
Note differences in “normal” state for
plant/animal cells



The more concentrated solution is Hypertonic
compared to the solution with less solutes. The
water will always try to rush in to make the more
concentrated solution less hypertonic
The less concentrated solution is referred to as
Hypotonic, water will attempt to leave this
compartment & decrease concentration of the solution
with more solute
When two compartments are equally concentrated
they are Isotonic with respect to each other,& there’s
no net diffusion of water
http://www.youtube.com/watch?v=
eQsAzXr0UCU osmosis demo
Examples of problems that
living cells face all the time

Simple animal cells (paramecium) in fresh water
habitats are surrounded by a hypotonic solution
and constantly need to expel water using
contractile vacuoles to prevent swelling &
lysis

Cells in marine environments are surrounded by
a hypertonic solution, and must actively pump
ions into their cells to reduce their water
potential and so reduce water loss by osmosis
Marine & Freshwater fish-homeostasis response:
Freshwater fish- pump water out to keep from
exploding. Marine fish-take in ions (salts) to keep all the
water from leaving their body
Plant Example

Plant roots may be in a hypotonic environment. Since
more water/ less solute is outside roots cells, water
rushes into the plant cells (by osmosis). Cells swell
against the cell wall.

TURGOR PRESSURE is the pressure that water
molecules exert against the cell wall
 Force gives the plant rigidity, and provides structural
support

You have probably experienced this with lettuce and
celery that have been in the fridge too long. They are
wilted and no longer crisp because they have lost their
Turgor Pressure

Red Onion Skin


(a) Hypotonic - cells are pressed against
cell walls
(b) Hypertonic - cells contract and pull
away from cell walls
3.Facilitated Diffusion
-The transport of substances across a membrane by
a
trans-membrane protein molecule
-No energy is involved -substances can
only move down their concentration gradient

4 Steps




Molecule binds to carrier protein
Carrier protein changes shape
Molecule released on other side of
membrane
Carrier protein returns to original shape
2 kinds of pump proteins

Carrier Proteins have a binding site for a
specific solute and constantly flip between two
states so that the site is alternately open to opposite
sides of the membrane


The substance will bind on the side where it is at a high
concentration and be released where it is at a low
concentration
ION Channel Proteins form a water-filled
pore or channel in the membrane

This allows charged substances (usually ions) to diffuse
across membranes. (Most channels can be gated (opened
or closed), allowing the cell to control the entry and exit of
ions.)
review video
Exit Slip
1. How are diffusion and
facilitated diffusion similar?
How are they different?
5-2 Active Transport
Objectives



Distinguish between passive and
active transport
Explain how the sodium-potassium
pump operates
Compare endocytosis and exocytosis
Active Transport
-when cells must move materials up their
concentration gradient, from an area of
lower to an area of higher concentration
2 ways:
1.
Cell Membrane pumps -Sodium-potassium pump
2.
Vesicles - Macromolecule exchange
- Endocytosis
- Exocytosis
1. Active
Transport
(pumping)
•Pumping of substances across a membrane
by a trans-membrane protein pump molecule
•The protein binds a molecule of the substance to be
transported on one side of the membrane, changes
shape, and releases it on the other side.
• REQUIRES ENERGY: An active process
• Use ATP -into ADP + P- use the energy
released to change shape and pump the
molecule
The Na+K+ Pump -This transport protein is
present in the cell membranes of all animal
cells and is the most abundant and important
of all membrane pumps
3 Sodiums (Na) out for every 2 Potassiums (K) in
Exchange of 3 NA for 2 K -creates an
electrical gradient across the cell
membrane
The outside of the membrane becomes positively charged
(+) & the inside negatively (-) charged
-Important for understanding electrical impulses like in
nerve cells
2. Vesicles

The processes described so far only apply
to small molecules

Large molecules (such as proteins,

Endocytosis & Exocytosis- both
polysaccharides and nucleotides) and even
whole cells are moved in and out of cells by
using membrane vesicles
energy- so are active transports
require
Endocytosis-
the process by which cells ingest external
fluid, macromolecules & large particles
Endocytosis



Materials are enclosed by a fold of the cell membrane,
which then pinches shut to form a closed vesicle
When the materials and the vesicles are small
(such as a protein molecule) the process is
known as pinocytosis (cell drinking)
If the materials are large (such as a white
blood cell ingesting a bacterial cell) the process
is known as phagocytosis (cell eating)
Endocytosis
Pseudopodia of a phagocytic cell
Exocytosis
 Essentially
endocytosis in reverse
 Vesicles in the cytoplasm fuse
with the cell membrane & empty
their contents outside the cell
Summary of Membrane Transport
uses
energy
uses
proteins
specific
controllable
Simple
Diffusion
N
N
N
N
Osmosis
N
N
Y
N
Facilitated
Diffusion
N
Y
Y
Y
Active
Transport
Y
Y
Y
Y
Vesicles
Y
N
Y
Y
method
Membrane transport
Small molecules
passive transport
simple diffusion
active transport
facilitated diffusion
water
channels
nonpolar
permeases
ions
pumps
cootransporters
Large molecules
endocytosis exocytosis pinocytosis
ENDOCYTOSIS
EXOCYTOSIS