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CELLS
The Smallest Unit of Life
Cell Discoveries
Anton vanLeeuwenhoek
– Made the first microscope that could view
individual cells.
– Saw cells in his tooth scrapings
http://www.ixedu.com/es/celula/Multimedia/Microscopio/Historia.htm
http://www.hps.cam.ac.uk/whipple/explore/microscopes/adutchpioneer/
Robert Hooke
Gave cells their name after he saw them
through the microscope
Thought they looked like “cells” or rooms
of the monastery
http://askabiologist.asu.edu/research/buildingblocks/rhooke.html
http://kmoddl.library.cornell.edu/biographies/Hooke/
Schleiden & Schwann
 Schleiden was a
botanist who said that
all plants were made
of cells
http://www.answers.com/topic/matthias-jakob-schleiden?cat=technology
 Schwann was a
zoologist who said
that all animals were
made of cells
http://www.britannica.com/eb/art-14156/Theodore-Schwann?articleTypeId=1
Cell Theory
1. All living things are made of cells.
2. Cells are the basic unit of
structure and function of living
things.
3. All cells come from pre-existing
cells.
What is a Cell?
The simplest unit of structure and function
for every living thing
Unicellular – single celled organism
• EX: Ameoba, paramecium
Multicellular – organism made of many
cells
• EX: humans, plants
Types of Cells
Prokaryotic
– Cells without a nucleus
• Bacteria only
Eukaryotic
www.med.sc.edu:85/fox/e_coli-dk.jpg
– Cells with a nucleus
• EX: Plant, Animal, Fungus & Protist
http://library.thinkquest.org/03oct/00520/gallery/photos/prokaryote.jpg
(nucleus)
http://library.thinkquest.org/03oct/00520/gallery/photos/prokaryote.jpg
Structure vs. Function
The shape or structure of a cell determines
its function.
– EX: red blood cell is small to fit through
small blood vessels but has a lot of surface
area to carry oxygen
http://www.britannica.com/eb/art/print?id=88528&articleTypeId=0
– EX: nerve cells are long and branched to send
messages quickly
http://www.dkimages.com/discover/Home/Science/Biology/The-Cell/The-Cell-27.html
What’s in a Cell?
Organelles
– like tiny organs in cells
– carry out specialized jobs
– Most cells have same organelles, but some
only found in specific type of cells
http://www.cellsalive.com/cells/cell_model.htm
Organelles
“tiny organs”
1. Cell Wall
 Only found in plant cells and bacteria
 Provides protection and allows materials
to pass from one cell to another
Like the walls of the
school
http://biology.unm.edu/ccouncil/Biology_124/Images/cellwall.jpeg
2. Cell Membrane
 The outer boundary of an animal cell and the
second layer of protection for a plant cell
 Selectively permeable – lets some things in
easily but not others (homeostasis)
 Also known as the phospholipid bilayer
 Like a security guard
www.che.vt.edu/Sum/images/cell
-membrane.gif
3. Nucleus
–
–
–
Control center of the cell
Contains DNA
Like the brain
www.nsf.gov/news/overviews/biology/interact05.jsp
http://www.public.iastate.edu/~ttt356/Nucleus.jpg
4. Cytoplasm
- Material between the cell
membrane and nucleus
- Provides a medium (substance)
to move nutrients through
- Reactions occur here
- Organelles found here
- Jelly-like
5. Rough & Smooth
Endoplasmic Reticulum
 “Rough” because attached ribosomes make it look
bumpy
 Checks proteins to make sure they are made
correctly.
Packages molecules
Like the Highways
www.biologycorner.com
http://www.biology.arizona.edu/CELL_BIO/tutorials/pev/graphics/smooth_er.gif
6. Ribosomes
 The smallest organelles
 These make proteins & other cell parts
 Some float in the cytoplasm; some are attached to
other organelles.
Like factories
http://genome.imim.es/courses/Madrid04/exercises/ensembl/images/ribosome.jpg
http://www.nsf.gov/news/overviews/biology/assets/interact05.jpg
http://ghr.nlm.nih.gov/handbook/illustrations/cellgolgi.jpg
7. Golgi Apparatus
 “Mailroom” of the cell
 Sorts, packages & exports proteins
Like the UPS
http://www.daviddarling.info/images/Golgi_apparatus.jpg
8. Lysosomes
 “Kamikaze” organelle
 They destroy bad proteins and damaged
organelles
 Enzymes assist
 Like a garbage
truck
http://www.molecularexpressions.com/cells/lysosomes/images/lysosomesfigure1.jpg
9. Mitochondria (-ion)
 Powerhouse of the cell
 Makes ENERGY!
 Like the
electric co.
http://kentsimmons.uwinnipeg.ca/cm1504/Image110.gif
10. Centrioles
Play an important
roles in cell division
Come in pairs
Animal cells
Like a filing
cabinet
http://3dbiology.pbworks.com/f/centrioles_cropped.jpg
11. Cilia
Hair-like
Useful for:
– Movement
– Protection
– Food gathering
Like a broom
12. Flagella (-um)
 Tail-like/whip-like
 Useful for movement
 Mostly in protist
13. Vacuole
 Storage organelle for food, water & wastes
 Huge in plant cells for the storage of water
 Many small vacuoles in animal cells
 Like a trash can or refrigerator
http://www.daviddarling.info/images/contractile_vacuole.gif
http://www4.alief.isd.tenet.edu/cahowe/PreAPBio/Projects/Cell_files/slide0013_image053.jpg
14. Chloroplast
 Contains chlorophyll
 PHOTOSYNTHESIS
 Like solar panels
http://www.s-cool.co.uk/alevel/assets/learn_its/alevel/biology/cells
-and-organelles/organelles/chloroplast-b.gif
http://www.scar.utoronto.ca/~olaveson/chloroplast-Sadava.jpg
Plant Cells vs. Animal Cells
 Plant Cells
–
–
–
–
Cell wall
Chloroplasts
Large vacuole
Square
www.molecularexpressions.com
 Animal Cells
–
–
–
–
Cell membrane
No chloroplasts
Small vacuole
Many shapes
http://encarta.msn.com/media_461540224_761563786_-1_1/animal_cell.html
•Nucleus
•Chloroplast
•Membrane
•Cell Wall
•Mitochondria
•Vacuole
•Golgi
•Ribosomes
Stem Cells
 Unspecialized cells
Have the ability to become any of the 220
different human cell types
Totipotent = total potential
Pluripotent = limited potential
Membranes & Transport
Gateways of
cells & organelles
Membrane Structure
Phospholipid Bilayer
– 2 layers of phospholipids
• Hydrophilic phosphate heads
• Hydrophobic lipid tails
– Innermembrane proteins
– Surface carbohydrates
– Surface lipids/cholesterol
Structure
http://www.bioteach.ubc.ca/Bio-industry/Inex/
http://www.biology.iupui.edu/biocourses/N100H/cells.html
http://commons.wikimedia.org/wiki/Image:Cell_membrane_detailed_diagram.svg
Passive Transport
 Does not require energy
 [High]  [Low]
1. Diffusion
2. Osmosis
3. Facilitated diffusion
1. Diffusion
Occurs across the phospholipids
– CO2
– O2
– Urea
Lab Information on Diffusion
Dialysis tubing acts as a semipermeable
membrane
Which materials can pass through the
pores?
Which cannot permeate the bag?
Animation
Dialysis
http://www.ualr.edu/botany/osmosis.jpg
2. Osmosis
Diffusion of water
Water moves from
– High [water]  low [water]
– Hypotonic [solute]  hypertonic [solute]
Animation
http://commons.wikimedia.org/wiki/Image:Osmotic_pressure_on_blood_cells_diagram.svg
http://commons.wikimedia.org/wiki/Image:Turgor_pressure_on_plant_cells_diagram.svg
Kidney Function
• Vessels bring waste-
filled blood to kidneys for
filtering.
• Membranes in the
kidneys let urea leave the
blood to go into the
ureter.
•Urea becomes urine and
collects in the bladder.
Dialysis
Dialysis
http://www.biotopics.co.uk/human2/andial.html
3. Facilitated Diffusion
Molecules moving from [high]  [low] but
are too big to move between phospholipids
Requires a
membrane carrier
(facilitator)
Glucose uses this
http://www.biology.arizona.edu/chh/problem_sets/kidneysmetals/07t.html
Active Transport
Requires ATP energy
– ATP pumps
– Endocytosis
– Exocytosis
Often goes against concentration gradient
Endo & Exocytosis
http://www.dnatube.com/view_video.php?viewkey=6ebda4840e7360ce6e7e
http://en.wikipedia.org/wiki/Phagocytosis
The Cellular Circle of Life
http://ebiomedia.com/prod/LC/LCcellunit.html
CELLULAR ENERGETICS
The Chloroplast
http://www.ualr.edu/botany/chloroplast.jpg
Autotrophs vs. Heterotrophs
Autotrophs
– Make their own food for energy
– Ex: Plants
Heterotrophs
– must obtain their energy from other organisms
– Ex: Animals & Fungi
Energy….
 The ability to do
work
 Purpose of
photosynthesis is to
make energy!
 sunlight energy is
changed into
chemical energy
Bonds & Energy
 Chemical energy is located in chemical
bonds of sugars & starches
 Breaking bonds releases energy
Light Use in Plants
ROYGBIV
 Light wavelengths primarily used by
plants are R and B I
 They do not use G since this is
reflected
Photosynthesis requires pigments…
http://botit.botany.wisc.edu/images/130/Ferns/Gameto
phyte_Images/Chloroplasts_MC.low.jpg
 Chlorophyll
– primary green pigment
– found in chloroplasts
 Other Pigments
–
–
–
–
http://i1-news.softpediastatic.com/images/news2/Plant-PigmentsEnhance-Iron-Absorption-2.jpg
Yellow (squash)
Orange (carrots)
Red (tomatoes)
Also seen in fall leaves
http://www.betterbudgeting.com/images/ph03642i.jpg
Photosynthesis = Energy!
Light energy  chemical energy 
kinetic energy!
Light
Photosynthesis
Sugar
Respiration
Energy!
FORMULA
6CO2 + 6H2O  C6H12O6 + 6O2
carbon dioxide + water  glucose + oxygen
http://www.grographics.com/risd/DmInfoBre
ath/1st-install/images/infobreath-mark.jpg
http://extension.missouri.edu
/xplor/agguides/hort/g06021.
htm
http://library.thinkquest.org/
C004535/media/pea_leaf_sto
mata.gif
http://www.hightechlandscapes.com/hig
htechlandscapes/images/watering_plants
.jpg
http://www.pbs.org/wgbh/nova/methuselah/photosynthesis.html#
Photosynthesis Prose
Adapted from PBS.org
Photosynthesis, the trapper of light;
it's needed for life to exist.
Plants use the process to make food;
without it most life would desist.
The process begins with plain water
but not from the tap does it flow.
Some water is made within leaf cells
and some is sucked up from below.
With energy gained from sunlight,
the Hs are stripped from each O.
The oxygen atoms form twosomes,
and out of the leaf they all go.
Meanwhile CO2 has just entered
through holes in the leaf called
stomata.
The gas is exhaled by Earth's creatures,
including all vertebrata.
But the plant has a goal that is bigger in
scope- it's out to make food it can keep.
It builds a big structure with C, H, and O;
it's glucose, and boy is it sweet.
Some folks get a kick from equations,
which explain things by some kind of
law.
If by chance you are one of these people,
then this explains what you just saw6CO2 + 6H2O  C6H12O6 + 6O2
CELLULAR
ENERGETICS
RESPIRATION
Respiration
ATP production from the breakdown of
organic compounds
Anaerobic Respiration
– No oxygen
– Occurs in cytoplasm
Aerobic Respiration
– Oxygen
– Occurs in mitochondria
The Respiration Formula
C6H12O6 + 6O2  6CO2 + 6H2O
glucose + oxygen  carbon dioxide + water
http://www.isleofprinting.co
m/images/artsale/eat.jpg
http://www.luckeygraphicdesi
gn.com/newsite/inhale_sm.jpg
http://www.grographics.com/risd/DmInfoBre
ath/1st-install/images/infobreath-mark.jpg
http://www.eons.com/images/
cms/7594_image_file_1.jpg
3 Main Stages of Respiration
Glycolysis
Kreb’s Cycle
Electron Transport Chain
ATP is made in 2 different ways during
respiration…
http://www.langara.bc.ca/biology/mario/Assets/pyruvatefate.jpg
The Energy Promiseland:
The Mitochondria
ATP
Oxygen
ATP
ATP
ATP
ATP
ATP
http://ebiomedia.com/prod/viz/Viz3.html
PLANTS vs. ANIMALS
Animals
– Respiration ONLY
Plants
– Photosynthesis AND
– Respiration
– Have both chloroplasts AND mitochondria
A Tour of the Cell
 The National Science Foundation Tour of
the Cell http://www.nsf.gov/news/overviews/biology/interactive.jsp
An amazing animation of the Inner Life of
the Cell http://www.studiodaily.com/main/searchlist/6850.html
Another Amazing Video – Flu Attacks!
http://www.npr.org/templates/story/story.php?storyId=114075029