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Review of Cells & Cell
Structures
On the following slides, the yellow sections are the
main points; summarize the slides for your notes.
Underlined words = vocabulary!
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Cell Brainstorm
 Draw a large thunder cloud in your notebook. Take
a minute to brainstorm anything and everything that
you know about cells within the “storm”.
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http://www.nature.com/
naturejobs/2007/07060
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http://www.alternativecancer.net/images/Cancer_cell,%20brain.jpg
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Theories vs Hypotheses – What is
the difference?
 A hypothesis is a tentative, testable statement for a
specific problem or question.
 A scientific theory and is well-established, highlyreliable explanations of events [natural and physical]
from multiple, independent theorists.
 Atomic Theory
 Cell Theory
 Theory of Evolution
 Theories may change as new areas of science and
new technologies are developed, providing new
information.
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Robert Hooke
 All living things are composed
of one or more cells.
 In 1665, the scientist Robert
Hooke first viewed plant cells
in cork tissue.
 Hooke coined the term "cells“
because the boxlike cells of
cork reminded him of the
cells of a monastery.
http://es.wikipedia.org/wiki/Robert_
Hooke
Hooke, Robert: cork cell structure and sprig of sensitive plant.
Photograph. Encyclopædia Britannica Online. Web. 26 Sep. 2010
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What is the Cell Theory?
 Years after Hooke, other scientists continued
to study cells and added new information to
the initial observations.
 The major concepts surrounding cells are
now known as the cell theory.
 The cell theory states:
1. All living things are composed of cells.
2. Cells are the basic units of structure and
function in living things.
3. New cells are produced from existing
cells.
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Types of Cells
 Review of prokaryotes vs eukaryotes from middle
school science.
Prokaryote
Simple cell holding
genetic material
Eukaryote
Living
DNA
Plasma membrane
AKA bacteria
Cell wall
Ribosomes
Unicellular
no nucleus (DNA is
free floating)
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Complex cells;
found in animals,
plants, protists, &
fungi
nucleus + membrane
bound organelles
Example:
Escherichia coli
(E coli) bacteria is
the common cause
of food poisoning.
http://www.greenfacts.org/images/glossary/bacteria.jpg
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Antoine Leeuwenhoek
Textbook Reference pg. 171, 1067-1065
RKDimages, Art-work number 16081, as Portrait of Anthony van
Leeuwenhoek (1632-1723), circa 1680 (1678-1682).
 Antoine van Leeuwenhoek designed an early first
compound light microscope (~1668).
 We use a microscope to study cells.
 Microscopes magnify cells to see more of the structures
and details within them.
Replica of the
microscope
designed by
Leeuwenhoek.
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Organelles
http://upload.wikimedia.org/wikipedia/commons/thumb/6/63/Bi
ological_cell.png/350px-Biological_cell.png
Textbook Reference pg. 173
 A structure inside most cells that is surrounded by a
membrane that performs a specific function is called an
organelle (“little organ”).
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Review of Organelles &
Cellular Membranes
 The information on the following slides should be
held within three different diagrams; find the arrow to
identify the organelle.
Image
http://waynesword.palomar.edu/images/plant3.gif
Cell Wall
Textbook Reference
pg. 179-180
 The cell wall is present in all plants, algae, fungi, and
prokaryotes (bacteria!).
 Its function is to provide support and protection for
the cell; it surrounds the cell membrane.
Image
Plasma Membrane
http://media1.shmoop.com/images/biology/biobook_cells_12.png
Textbook Reference pg. 175-178
 The plasma membrane is a complex layer of lipids and
proteins (phospholipid bilayer) that surrounds cell and
regulates materials that go in and out of the cell;
maintains homeostasis.
Image
A Phospholipid Bilayer
Image Copyright © The McGraw-Hill
Companies.
All rights reserved.
Image
Cytoplasm
Textbook Reference pg. 181
 Cytoplasm is
the material
between the
cell membrane
and nucleus.
 It is a thick fluid
made mostly of
water; jelly like.
 The function of
the cytoplasm
is to contain
the organelles.
Image
Cytoskeleton
Textbook Reference pg. 185
 The network of threadlike protein fibers
(microfilaments and
microtubules) extending
through cytoplasm is
called the cytoskeleton
(shown in yellow on the
next slide).
 This “skeleton” gives
cell shape and support,
helps transport
materials, and
sometimes enables cell
to move.
http://media1.shmoop.com/images/biology/biobook_cells_1.png
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http://www.immediart.com/catalog/images/big_images/SPL_6_P780110Fibroblast_cells_showing_cytoskeleton.jpg
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Nucleus
Textbook Reference pg. 180
 The nucleus contains the genetic material (DNA)
and controls the cell’s activities.
 It is surrounded by a double membrane called the
nuclear envelope.
Image
Nucleolus
Textbook Reference pg. 181
 The nucleolus is inside the nucleus where
ribosomes are produced.
Image
Ribosomes
Textbook Reference pg. 181
 Ribosomes are
found loose in
cytoplasm or
bound to other
organelles.
 They produce
proteins from
instructions within
mRNA.
Image
Mitochondria
Textbook Reference pg. 185
 Mitochondria
convert glucose
into ATP (cell
energy).
 A mitochondrion
contains its own
DNA.
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Chloroplasts
Textbook Reference pg. 184
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 Chloroplasts
also contain their
own DNA and
capture energy
from sunlight
and convert it to
glucose
(photosynthesis).
 They are found
in plants, algae,
and
photosynthetic
bacteria.
The photo to the right shows leaf
cells of an aquatic plant
called Elodea.
The lines are cell walls.
The green spots are chloroplasts
which move along the cell walls
in this plant.
If a chloroplast appears to be
blurry, it is because it is moving
within the cell. Image
Image
Lysosomes
Textbook Reference pg. 183
 Lysosomes are sac like organelles filled with
enzymes and help to digest and recycle materials
within the cell (to breakdown carbohydrates, proteins,
and lipids into H, O, C, etc).
Image
lysosome: intracellular digestion. Art. Encyclopædia
Britannica Online. Web. 26 Sep. 2010
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Endoplasmic Reticulum
Textbook Reference pg. 181-182
 The ER is a folded
network of
membranes.
 Rough ER – studded
with ribosomes
 Smooth ER – no
ribosomes
 Both rough and
smooth ER build
lipids and remove
toxins for the cell.
 Because rough ER,
has ribosomes, it can
also synthesize
proteins.
Image
Golgi
Textbook Reference pg. 182
Image
 The Golgi
apparatus
(AKA Golgi
Body) is a
series of flat,
membranebound sacs.
 The Golgi
apparatus
modifies, sorts
and packages
materials for
storage or
transport
outside the
cell.
 Vacuoles are the
storage
compartments
within cells.
 Plant cells often
have large
vacuoles, while
animal cells
have small ones,
if any.
 Some singlecelled life forms
use vacuoles to
pump excess
water out of the
cell (contractile
vacuole).
Vacuole
Textbook Reference pg. 183
Image
Amoeba proteus
a) contractile vacuole
b) food vacuole
c) nucleus
Image
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Flagella
Textbook Reference pg. 187
 Flagella (1 flagellum) are long, whip like structures that
some cells used for movement.
 Some forms of single-celled life use flagella that spin like
a propeller.
 Mammalian sperm have these flagella (long tails) to help
them reach an ova.
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Chytrids (Chytridiomycota)
These fungi are mostly aquatic,
are notable for having a flagella
on the cells, and are thought to
be the most primitive type of
fungi. Image
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Cilia
& Pili
Textbook Reference pg. 187, 487
 Cilia and pili (1 cilium or pilus) are tiny, hair like
projections on the surface of some cells.
 Some forms of single-celled life use for movement and
to attach to surfaces.
 Cilia are found in the Fallopian tubes of mammals to
move ova (egg cells) to the uterus. In the respiratory
system, cilia clean debrisImageand move fluid.
“Our nasal passages are filled with cilia which are
constantly in motion, sweeping particulates into gunk
deposits that we get rid of later in various ways.” Image
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