http://www.topnews.in/files/port-shipping.jpg
Chapter 7.3 and 7.4
Cell Transport
http://www.tsicontainers.com/images/Shipping%20Port.jpg
Chapter Mystery?
Chapter 4 Vocab
1.
Active transporttransport across the cell
membrane that requires
energy
2. Passive transportmovement across the cell
membrane that does not
require energy.
3. Concentration gradientdifference of
concentration across a
space
4. Osmosis
5. Diffusion
6. Facilitated Diffusion
7. Aquaporin
8. Endocytosis
9. Exocytosis
10.receptor protein- a protein
on the cell membrane that
receives a signal molecule.
11. Hypertonic
12. Hypotonic
13. Isotonic
Main Function of the Cell Membrane
• Membranes are selectively permeable so they
control what moves in and out of the cell
– Based on size and polarity
The Cell Membrane
http://micro.magnet.fsu.edu/cells/plasmamembrane/images/plasmamembranefigure1.jpg
The Phospholipid bilayer
• Every single cell
exists in a liquid
environment
• Bilayer made of
phospholipids
– Hydrophilic
Heads-love water
(polar)
– Hydrophobic tailshate water (non
polar)
http://academic.brooklyn.cuny.edu/biology/bio4fv/page/lipos.gif
https://www.youtube.com/watch?v
=_3lNYbt0eAs
What are polar and nonpolar
molecules?
http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20101/Bio%20101%20Lectures/chemistry/chemis4.gif
Passive Transport: Requires NO
Energy
• Every cell exists
in a liquid
environment.
• Every cell must
maintain
homeostasis
• Cells must
regulate transport
across the cell
membrane
http://www.google.com/imgres?q=passive+transport&um=1&hl=en&rlz=1T
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_transport&docid=0VcILTJKWByLM&imgurl=http://image.absoluteastronomy.com/images/encyclopediaima
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44&hovh=179&hovw=281&tx=143&ty=89&sig=107888942202169124570
&page=2&tbnh=113&tbnw=177&start=13&ndsp=12&ved=1t:429,r:1,s:13
Concentration Gradients: the
differences in concentration across a
space.
http://brainchemist.wordpress.com/2011/01/21/diffusion-mri-ch-1-introduction-to-diffusion-magneticresonance/
Equilibrium
• B. equal
concentrations across
a space.
http://academic.kellogg.cc.mi.us/herbrandsonc/bio111/images/water/water.3.jpg
Diffusion: the movement from an
area of high concentration to an
area of low concentration.
• 1) a difference in
concentration exists
across the cell
membrane
• 2) diffusion occurs
down the gradient.
http://www.biologycorner.com/resources/diffusion-animated.gif
•
Cell membrane is selectively
permeable
A. repels non
polar molecules
and ions.
• B. polar
molecules and
very small
molecules can
diffuse across the
cell membrane.
http://www.geosciences.unl.edu/~dbennett/images/Cell_membrane.gif
Ion Channel: a polar pore through
which ions can pass into a cell.
• A. some molecules
cannot pass directly
through the cell
membrane.
• B. Ion channelsallows polar
molecules, (like
ions) pass into the
cell.
http://www.agen.ufl.edu/~chyn/age2062/lect/lect_06/4_20B.GIF
Facilitated Diffusion: Sugars and
amino acids
• A. carrier proteins
-bind to substances
outside the cell and
carry it inside.
• B. Amino acids
and Sugars
• C. Down the
concentration
gradient.
• D. NO ENERGY
REQUIRED
ell/cludiant/sianel.gif&imgrefurl=http://www.aber.ac.uk/gwydd-cym/cellbiol/transport/index.htm&h=161&w=157&sz=16&hl=en&start=4&tbnid=ZvBWMBrJP6UWrM:&tbnh=98&tbnw=96&prev=/images%3Fq%3Dmembra
Osmosis: the diffusion of water
through a selectively permeable
membrane.
• A. uses a
concentration
gradient
• B. passive transport
• C. Aquaporins-water
channel proteins
• D. This is a type of
facilitated diffusion
http://www.bigbrandwaterfilter.com/water_filter_images/waterdrop_embossed.gif
Hypertonic solutions
• 2. Water moves out of
the cell-causes cell to
shrink, called a
Hypertonic solution
Hypotonic Solutions
• 3. Water moves into
the cell-causes cell to
swell and burst, called
a hypotonic solution
http://www.biologycorner.com/resources/hypotonic.gif
Isotonic solutions
• 4. No net movementcell remains the same,
called a Isotonic
solution.
http://www.biologycorner.com/resources/isotonic.gif
•
How to Deal with osmotic
pressure?
A. contractile
vacuole-a water
pump found in
paramecium
• B. cell walls- keeps
central vacuole
from over
expanding.
• Large organisms
cells are bathed in
blood or isotonic
solutions
http://science.kennesaw.edu/biophys/biodiversity/protista/pictures/paramecium.gif
http://imcurious.wikispaces.com/Midterm+Exam+2010+Review+P2
Review Questions
• 1. What is a concentration gradient?
• 2. Describe the movement of molecules
during diffusion.
• 3. Can polar molecules pass through the cell
membrane? Why or why not?
• What is a aquaporin?
• 5. What is the difference between a
hypotonic, hypertonic and an isotonic
solution.
• 6. What is passive transport?
Label the following cells as Isotonic,
hypotonic, or hypertonic
Image from
www.ndpteachers.org/perit/biology_image_galle...
Active Transport: Requires ATP
• A Requires ATP
– 1. Carrier proteins-act
as pumps
– 2. Against the
concentration gradient.
• B. Sodium-Potassium
Pump
– 1. Sodium ions-more
on outside of cell
– 2. Potassium ionsmore on inside of cell
http://www.biologie.uni-hamburg.de/b-online/library/biology107/bi107vc/fa99/terry/images/ATPpumA.gif
How do you get Big Molecules
across the cell membrane?
Answer: Endocytosis and
Exocytosis
Endocytosis: too large to pass
through the cell membrane.
• A. polysaccharides
and proteins
• B. use a vesicle
• C. cell forms a pouch
around the substance.
• D. phagocytosisengulfing prey.
http://www.youtube.com/watch?v=aWItglvTiLc&feature=related
http://www.biologie.uni-hamburg.de/b-online/library/biology107/bi107vc/fa99/terry/images/RectmAnA.gif
Endocytosis
Exocytosis
http://www.sirinet.net/~jgjohnso/exocytosis.jpg
Exocytosis
• A. the movement out
of the cell using a
vesicle.
• B. the vesicle fuses
with the cell
membrane.
• C. golgi body-proteins
modified here are
released from the cell
using exocytosis
http://www.stanford.edu/group/Urchin/GIFS/exocyt.gif
Review Question
• 7. What is active transport?
• 8. How does a sodium-potassium pump
work?
• 9. What are the similarities and differences
between endocytosis and exocytosis?
• 10. What is the function of a receptor
protein?
How do multicellular organism
maintain homeostasis?
• Cell specialization- in
order for cells to be
effective, they must
work together.
Teamwork
http://www.ptei.org/interior.php?pageID=42
Levels of Organization in
multicellular organisms
http://www2.lbsdk12.com/science/Anatomy/levelsoforganization.jpg
Levels of Organization
• Cells- group of ORGANELLES working
together to perform a particular function.
• Tissue- a group of cells working together to
perform a particular function.
• Organ- a group of tissues working together
to perform a particular function.
• Organ system- a group of organs working
together to perform a particular function.
• Organism- all organ systems working
together to maintain homeostasis
How do you send a text message
to a cell?
http://www.biologycorner.com/APbiology/cellular/(notes)cell_membrane.html
Answer: Membrane Receptor
Proteins Receive Information
• 1. Cells release signal
molecules that carry
info (hormones).
• 2. Receptor proteinsbinds to specific
receptor molecules
• 3. They can speed up
or slow down cell
activities.