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CHAPTER 7:
CELL STRUCTURE
AND
FUNCTION
Scanning Electron Microscope: Specimen Cells
http://micro.magnet.fsu.edu/primer/java/electronmicroscopy/magnify1/index.html
Fat cells
Nerve Cells
Red Blood Cells
More Cells
More Cells!
7-1 Life Is Cellular
A. The Discovery of the Cell
1. Early Microscopes
• Robert Hooke- Used compound microscope
to look at a slice of cork
• Anton van Leeuwenhoek- Observed tiny living
things in pond water
2. The Cell Theory
• Mathias Schleiden-Concluded all plants are made of
cells
• Theodor Schwann- Stated all animals are made of
cells
• Rudolf Virchow- Concluded new cells come from
existing cells
Cell Theory:
•  All living things are composed of _____
cells
•  Cells are the basic units of structure and
function in living things
•  New cells are produced from
Existing cells
____________
B.
Exploring the Cell
1. Electron Microscope (TEM & SEM)
-Specimen placed in a vacuum
http://www.mos.org/sln/sem/
2. Scanning Probe Microscope
-1990 development of fine probe microscope
ordinary air
-operates in _______________
-can even show samples in solution
C. Prokaryotes and Eukaryotes
0.2 micrometers
• cells vary in size from _________________1000 micrometers
___________________
• viruses are not cells
Prokaryotic cell
Cell membrane
Eukaryotic cell
Cytoplasm
Cell membrane
Organelles
Cytoplasm
Nucleus
Prokaryotes
Common to Both
before
 pro=__________
 contain
DNA
__________
 karyote= kernel
(nucleus)
 Cell
 generally smaller
membrane
 less complicated
 no
Membrane
bound
organelles
 Ex: Kingdom
Monera
- Eubacteria
- Archaea
Eukaryotes
true
 Eu= ___________
 Karyote=kernel
(nucleus)
 Generally larger
 Contain
membrane bound
organelles (“little
organs”)
 Ex:
Plants,
animals, fungi,
and protists
Eukaryotic Cell vs. Prokaryotic cell
http://www.wiley.com/legacy/college/boyer/0470003790/animations/cell_structure/cell_structure.htm
Venn Diagrams
7-2 Eukaryotic
Cell Structure(chart)
Section 7-2
Prokaryotes
Eukaryotes
Cell membrane
Contain DNA
ribosomes
Animal Cells
Centrioles
Lysosomes
Plant Cells
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Vacuoles
Mitochondria
Cytoskeleton
http://www.slideshare.net/mgsonline/prokaryotes-vs-eukaryotes
Cell Wall
Chloroplasts
Central Vacuole
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Additional Resources
•
•
Cell Organelles
http://www.wisc-online.com/objects/index_tj.asp?objID=AP11604
•
•
Journey into DNA
http://www.pbs.org/wgbh/nova/genome/dna.html#
•
•
Quiz
http://www.wisc-online.com/objects/index_tj.asp?objID=AP11604
•
•
Cytoskeleton
http://www.sumanasinc.com/webcontent/animations/content/intermediate_filaments.html
artists rendition of the plant cell
Section 7-2
Smooth endoplasmic
reticulum
Vacuole
Ribosome
(free)
Chloroplast
Ribosome
(attached)
Cell
Membrane
Nuclear
envelope
Cell wall
Nucleolus
Golgi apparatus
Nucleus
Mitochondrion
Rough endoplasmic reticulum
Plant Cell
artists rendition of an animal cell
Animal cell
http://www.wiley.com/legacy/college/boyer/0470003790/animations/cell_structure/cell_structure.htm
Animal Cell
Ribosome
(attached)
Nucleolus
Nucleus
Nuclear
envelope
Rough
endoplasmic
reticulum
Golgi apparatus
Ribosome
(free)
Cell
Membrane
Mitochondrion
Smooth
endoplasmic
reticulum
Centrioles
Parts Wanted
Advertising for Cells’ Organelles
Example:
HELP WANTED
Looking for a great opportunity to lead? Do you
enjoy making decisions for others? Is
guidance your strong point? If so, we are
seeking to fill a managerial position. We are
in need of a control center for a cell. Must be
able to operate a cell. Should have solid
experience reading and de-coding DNA.
Should exhibit strong leadership skills.
Benefits include: placement in low stress arm
cells, long life guaranteed. . You don’t die;
you just divide and multiply! If interested
contact The Body at 817-8WE-CELL.
7-3 Cell Boundaries
A. Cell Membrane
• Regulates what ___________
and __________
enters
leaves
the cell
• Provides protection and support
lipid bilayer
• Composed of a ______________
• __________________
are embedded in the
Protein molecules
bilayer; form channels and pumps to move
material across the cell membrane.
• _________________
are attached to some of the
Carbohydrates
proteins; allows cells to __________
one
identify
another.
Outside
of cell
CELL MEMBRANE
“FLUID MOSAIC”
Carbohydrate
chains
Proteins
“ID tags”
Cell
membrane
Inside
of cell
(cytoplasm)
Protein
channel
“transport”
http://www.susanahalpine.com/anim/Life/memb.htm
Lipid bilayer
“Phospholipids”
B. Cell Walls
• Found in plants, algae, fungi and
many prokaryotes
• Cell walls are porous enough to allow
water, oxygen, carbon dioxide easily
• Main function is to provide
support and protection for the cell
cellulose
• Plant cell walls made of __________
(carbohydrate fiber)
C. Diffusion Through Cell Boundaries
•All living cells exists in a liquid environment.
•Cell membranes regulate
the movement of molecules in and out of
the cell.
selectively permeable
•Cell membranes are _____________________
semipermeable
(aka: _______________)
•If substances can pass, then the cell
membrane = Permeable
•If substances cannot pass, then the cell
membrane= impermeable
1. Measuring Concentration
• Cytoplasm= Water and other substances
between the cell membrane and
the nucleus.
• Concentration= mass of solute/volume of
solution
• Example:12g salt/3L H2O= 4 g/L
60g salt/3L H2O= 20 g/L
5X more
concentrated
• Concentration gradient= unequal distribution
of particles
2. Diffusion
• Particles constantly collide and spread out randomly in
solution
high concentration _____
to a ____
low
• Particles move from a _____
concentration (with the concentration gradient); process is
diffusion
known as _________
• Diffusion continues until equilibrium is reached
• Equilibrium = When particles are evenly distributed in
solution
• Diffusion depends upon random particle movements,
without requiring the
substances diffuse across membranes ______
cell to use energy
_______
• The movement of particles will continue to move
equally across the cell membrane to maintain
equilibrium.
D.
Osmosis
• H2O passes easily across most membranes
•  Osmosis = The diffusion of water through a
selectively permeable membrane
Before
Osmosis
Selectively
permeable
membrane
After
Osmosis
water
solute
Figure 7-15 Osmosis
1. How Osmosis Works
Section 7-3
Left Beaker:
left side (low water
• More sugar molecules on the ____
concentration).
• High water concentration on the right side.
• The membrane is permeable to water but not sugar.
• Net movement of water from high water concentration to low
water concentration.
TYPES OF SOLUTIONS
Hypertonic Solution
“above strength”
High concentration of
Dissolved substances
In Solution
Isotonic Solution
“same strength”
Hypotonic Solution
“below strength”
Equal concentration of
dissolved substances
Low concentration of
dissolved substances
in solution
Cells in a hypertonic solution

In a hypertonic
solution, water
leaves a cell by
osmosis, causing
the cell to shrink.
H2O
H2O
Water Molecule
Dissolved Molecule
Cells in a hypotonic solution

In a hypotonic
solution, water
enters a cell by
osmosis, causing
the cell to swell.
H2O
H2O
Water Molecule
Dissolved Molecule
Cells in an isotonic solution

In an isotonic
solution, the
concentration of
dissolved substances
in the solution is the
same as the
concentration of
dissolved substances
inside the cell.
H 2O
H2O
Water Molecule
Dissolved Molecule
2. The effects of Osmosis on cells
(animal cells refer to figure 7-16)
Cells in a
hypertonic
solution
Cells in an
isotonic
solution
Cells in a
hypotonic
solution
E. Facilitated Diffusion
• Molecules, that cannot diffuse across the cell
membrane’s lipid bilayer on their own, can move
With the help of protein channels
move from high to low concentration
• Molecules still ___________________
Facilitated Diffusion
Section 7-3
Glucose
molecules
High
Concentration
Cell
Membrane
Low
Concentration
Protein
channel
F. Active Transport
• Movement of molecules against a concentration gradient
(from low to high)
• Requires energy
• Needs a transport protein or pump
Molecule to
be carried
Energy
Molecule
being carried
 Large molecules and clumps of material can be
taken into the cell by a process known as
___________.
endocytosis The two kinds of endocytosis are:
1. Phagocytosis= ‘Cell eating’
2. Pinocytosis= ‘cell drinking’
Exocytosis release of large amounts of material
 ___________=
endo/exocytosis
demonstration
Transport of Large Particles
• Endocytosis is a process by which a cell
surrounds and takes in material from its
environment.
Nucleus
Digestion
Exocytosis
Endocytosis
Wastes removal
1. interactive sites for cell membrane, diffusion, active, passive transport
Let’s Review:
PASSIVE TRANSPORT
1.Simple diffusion
(includes Osmosis)
*
No ATP
Hi-Lo
No protein
ACTIVE
TRANSPORT
2. Facilitated Diffusion
*
No ATP
* ATP required
Hi-Lo
Lo-Hi
Needs protein Needs Protein
7-4 The Diversity of Cellular Life
A. Unicellular Organisms (single celled)
• Unicellular organisms _________
outnumber multicellular
organisms
• Examples: Yeast, algae, bacteria
B. Multicellular Organisms (many celled)
• Cells become ___________
specialized to perform different
tasks
• Cells need to communicate and cooperate
C. Levels of Organization
•  The levels of organization in a multicellular organism
are:
individual CELLS
TISSUES
ORGANS
Section
Muscle cell
Smooth muscle
( ti ssue)
Stomach
(organ)
ORGAN
SYSTEMS
Digesti ve system
(organ system)
1. Tissues= Group of similar cells that perform a particular function
• Four types of tissue:
- muscle
- epithelial
- nervous
- connective
2. Organs= Groups of tissues
•
Ex. bicep muscle is mad of muscle, connective, and nervous
tissue
3. Organ Systems= Group of organs that work together to
perform a specific function.
California State Standards
1. Cell biology
a. Cells are enclosed in semipermeable membranes
that regulate their interactions with their
surroundings
c. Know prokaryotic cell differ from eukaryotic cells
e. Know the role of endoplasmic reticulum and golgi
apparatus in the secretion of proteins
g. Students know the role of mitochondria in making
stored chemical-bond energy available to cells
j. Students know how eukaryotic cells are given shape
and internal organization by a cytoskeleton or cell
wall or both.
Warm-up
Section 7-1
1. Name 3 scientists and their contribution
to science.
2. What is the cell theory?
3. What are the characteristics of
prokaryotes and eukaryotes. Use the
“thinking visually” box on page 173 to
answer this question.
Warm-up
Section 7-2
1.
2.
3.
4.
5.
Compare and contrast plant and animal
cells. Are they prokaryotic or eukaryotic?
Eukaryotic cells maintain shape and
internal organization with ….?
What is the function of the nucleus?
Where is chemical energy from food
converted to useable energy?
Where is light energy converted to
chemical energy in plants? What is this
process called?
Warm-up
Section 7-3
1.
2.
3.
4.
5.
6.
Describe the anatomy of a cell membrane.
What are the main functions of the cell
membrane and the cell wall?
What happens during diffusion?
What is osmosis?
Describe the terms hypotonic, hypertonic,
isotonic.
Compare and contrast passive and active
transport.
Warm-up
Section 7-4
1. What are the levels of
organization in a multicellular
organism?
2. What is cell specialization?
Provide 3 examples.
1. In many cells, the structure that
controls the cell’s activities is the
a) Cell membrane
b) Organelle
c) Nucleolus
d) Nucleus
2. Despite differences in size and
shape, all cells have cytoplasm and a
a. Cell wall
b. Cell membrane
c. Mitochondrion
d. Nucleus
3. If a cell of an organism contains
a nucleus, the organism is a (an)
a. Plant
b. Eukaryote
c. Animal
d. Prokaryote
4. Distinct threadlike structures
containing genetic information are
called
a. Ribosomes
b. Chromosomes
c. Nuclei
d. Mitochondria
5. Which organelle converts the
chemical energy in food into a form
that cells can use?
a. Nucleolus
b. Chromosome
c. Mitochondrion
d. Chloroplast
6. Cell membranes are
constructed mainly of
a. Lipid bilayers
b. Protein pumps
c. Carbohydrate gatess
d. Free-moving proteins
7. The movement of water
molecules across a selectively
permeable membrane is known as
a. Exocytosis
b. Phagocytosis
c. Endocytosis
d. osmosis
8. A substance that moves across
a cell membrane without using the
cell’s energy tends to move
a. Away from the area of equilibrium
b. Away from the area where it is less
concentrated
c. Away from the area where it is more
concentrated
d. Toward the area where it is more
concentrated
9. Which cell helps in gas
exchange in plants?
D. Stomata
10. A tissue is composed of a
group of
a. Similar cells
b. Related organelles
c. Organ systems
d. Related organs
Standardized Test Prep
1. Animals cells have all of the following
a.
b.
c.
d.
e.
EXCEPT
Mitochondria
Chloroplast
Nucleus
Cell membrane
Golgi apparatus
STP
2. The nucleus includes all of the following
a.
b.
c.
d.
e.
structures EXCEPT
Cytoplasm
Nuclear envelope
DNA
Nucleolus
Chromatin
STP
3.
Which statement best describes the expected result
when a typical cell is placed into fresh water?
a.
b.
Active transport of water into the cell would begin
There would be a net movement of water out of the
cell
There would be a net movement of water into the cell
Protein synthesis would begin
No change in the cell’s water content would occur
c.
d.
e.
STP
4. Which cell structures are sometimes
a.
b.
c.
d.
e.
found attached to the ER?
Chloroplasts
Mitochondria
Vacuoles
Nuclei
Ribosomes
STP
5. Which process always involves the
a.
b.
c.
d.
e.
movement of materials from inside the
cell to outside the cell?
Phagocytosis
Endocytosis
Diffusion
Exocytosis
Osmosis
STP
I.
II.
III.
Which of the following is NOT an example of active
transport?
Facilitated diffusion
Osmosis
Diffusion
a.
b.
c.
d.
e.
I only
III only
I and II only
II and III only
I, II, and III
6.
STP
7. E
8. B
9. D
How are prokaryotic and
eukaryotic cell alike? How do
they differ?