Download ALL LIFE IS CELLULAR!

ALL LIFE IS
CELLULAR!
(The rest is just details.)
A View of
the Cell
Images
Types
What do
they do?
What
about
cells?
Quiz
History &
Microscopes
Organelles
Membrane
Leaf
Cells
#1
Bacteria
#2
Cell
Images
Blood
Cells
Striated
Muscle
#3
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Cytoplasmic
streaming
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What am
I seeing?
NUCLEUS
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To
what am
I seeing?
What am I seeing?
 These are onion cells.
 The “boxes” are the actual cells
 What is the dark round structure inside
the cells?
 What are the “stringy” structures in some
cells?
 Go Back and click on these to find out.
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What
Is
This?
Various blood cells
What kind of blood cell is
this?
It is a Red Blood Cell
Also, known as an
Erythrocyte
Their function is to transport
oxygen throughout the blood.
What kind of blood cell is this?
It is a type of White Blood Cell.
White blood cells are known as
Leukocytes.
There are many kinds of
WBC’s. They work within the
immune system to fight
invaders. What are some types
of invaders?
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How
Big
Is it?
Actually, this is not big at all. It is a
bacterial cell and is about 1/10,000th
the size of the other cells you have
viewed.
 Are bacteria cells the same as all other
types of cells?
 How are bacterial cells classified?
 Are all bacteria harmful?
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Characteristics of
Bacteria Cells
 They are Prokaryotic Cells not Eukaryotic Cells
 This means they do not have membrane
covered nuclei or organelles inside. The DNA
is in a “region” of the cell, but they do have
ribosomes which don’t have a membrane.
 They have a cell wall but not made of cellulose
like plant cell walls. It is made of peptidoglycan
– a combination of protein and carbohydrates.
 All bacteria belong to Kingdom Monera and all
Monerans are prokaryotes and all prokaryotes
are Monerans.
Classifying Bacteria
 Shape
 Spherical
- Cocci / Coccus
 Example: Streptococcus pyrogenes
 Rod like
- Bacilli / Bacillus
 Example: Bacillus anthracis
 Spiral
- Spiralli / Spirallis
 Example: Vibrio cholerae
 Gram Staining Test Technique
Yuk! Strep
throat!
Light microscope image
What is this?
 The 3 types of muscle cells:
Skeletal
cardiac
smooth
 Can you see the striped appearance of these cells?
 “Striated” means striped – this is striated skeletal
muscle
 The stripes are a result of light and dark bands
within individual muscle cells called “sarcomeres”
 The striated muscle fibers are made up of actin and
myosin (proteins that can contract/shorten) which meet
like zipper teeth. A muscle contracts (shortens) when
the myosin and actin elements are pulled together
along their length.
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Muscle
slide
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leaf
Light microscope image
w/ Gram stain
Electron microscope image
•Determines the type of cell wall a bacteria has
•Slides are washed successively in the following
dyes: crystal violet, iodine, alcohol, safranin
•Gram positive organisms are purple (or bluish)
•Gram negative organisms are red
•Helpful in determining treatment for bacterial
infections – which medicine should you take?
Gram Negative
Gram Positive
Two major types of cells
 Prokaryotes
 Cells without true nucleus;
not surrounded by a
membrane
 Has DNA in a nucleoid
region
 No membrane-bound
organelles
 Has ribosomes
 Has a cell wall – not made
of cellulose like plant cell
walls; Made of
peptidoglycan – a
combination of protein
and carbohydrate
 Only bacteria are
prokaryotic cells
PROKARYOTES
 Eukaryotes
 Cells with a true
nucleus(DNA) surrounded
by a membrane
 DNA in a nucleus
 Organelles covered in a
membrane
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Plants
Animals
Fungi
One celled Protists
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Amoeba
Algae
Euglena
paramecium
EUKARYOTES
Plant and Animal
Cells
Two Basic Cell Types
Cells that do not contain internal
membrane-bound structures are called
prokaryotic cells.
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• The cells of unicellular bacteria do not
have membrane bound structures and are
therefore called prokaryotes.
PROKARYOTIC CELLS
EUKARYOTIC CELLS
PLANT CELLS
ANIMAL CELLS
The Life of a Cell
A View of the Cell
A cell is the
basic unit of life.
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The History of the Cell Theory
• Before microscopes were invented, people
believed that diseases were caused by curses
and supernatural spirits.
• As scientists began using microscopes, they
quickly realized they were entering a new
world–one of microorganisms.
• Microscopes enabled scientists to view
and study cells, the basic units of living
organisms.
Development of Light Microscopes
 The first person to record looking at water
under a microscope was Anton van
Leeuwenhoek.
 The microscope van Leeuwenhoek used is
considered a simple light microscope because
it contained one lens and used natural light to
view objects.
Development of Light Microscopes
Compound light microscopes use a series of
lenses to magnify objects in steps.
These
microscopes
can magnify
objects up to
1 500 times.
The Cell Theory
• Robert Hooke was an English scientist who
lived at the same time as van Leeuwenhock.
• Hooke used a compound light microscope to
study cork, the dead cells of oak bark.
Cells are the basic building blocks of
all living things.
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More
Info
here
The cell theory is made up
of three main ideas:
All organisms are composed of one or
more cells.
The cell is the basic unit of
organization of organisms.
All cells come from preexisting
cells.
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Electron
microscopes
Development of Electron Microscopes
 The electron microscope was invented in the 1940s.
 This microscope
uses a beam of
electrons to
magnify
structures up to
500 000 times
their actual size.
Development of Electron Microscopes
There are two basic types of electron microscopes.
The scanning electron microscope scans the
surface of cells to learn their three dimensional
shape.
The transmission electron microscope allows
scientists to study the structures contained
within a cell.
A prokaryotic cell does not have internal organelles
surrounded by a membrane. Most of a prokaryote’s
metabolism takes place in the cytoplasm.
2. DNA
• Ribosomes
(the dots)
6. Cytoplasm
3. Plasma membrane
4. Cell wall
5. Flagellum
This eukaryotic cell from an animal has distinct
membrane-bound organelles that allow different parts
of the cell to perform different functions.
1. Nucleus
2. Nucleolus
3. DNA/Chromosomes
4. Plasma membrane
5. Other Organelles
The membrane-bound structures within
eukaryotic cells are called organelles.
 Each organelle has a specific function that
contributes to cell survival.
• Separation of organelles into distinct
compartments benefits the eukaryotic
cells.
The nucleus is the central membranebound organelle that manages cellular
functions.
The Plasma Membrane
PLANT
CELLS
ANIMAL
CELLS
Cellular Boundaries
The plasma
membrane acts as
a selectively
permeable
membrane.
The cell wall
The cell wall is a
fairly rigid structure
located outside the
plasma membrane
that provides
additional support
and protection.
Nucleus and cell
control
Chromatin
Nuclear
Envelope
Nucleolus
Assembly, Transport, and
Storage
The endoplasmic
reticulum (ER) is
an organelle that
is suspended in
the cytoplasm
and is the site of
cellular chemical
reactions.
Assembly, Transport, and
Storage
Endoplasmic
Reticulum (ER)
Ribosomes
Assembly, Transport, and
Storage
Golgi
Apparatus
Vacuoles and storage
Vacuoles are membrane-bound spaces used for
temporary storage of materials. Notice the
difference between vacuoles in plant and animal
cells.
Animal
Cell
Vacuole
Plant
Cell
Lysosomes and recycling
Lysosomes are organelles that contain
digestive enzymes. They digest excess or
worn out organelles, food particles, and
engulfed viruses or bacteria.
Energy Transformers:
Chloroplasts and energy
Chloroplasts are
cell organelles that
capture light energy
and produce food
to store for a later
time.
Chloroplasts and energy
The chloroplasts belongs to a group of plant
organelles called plastids, which are used for
storage.
Chloroplasts contain green pigment called
chlorophyll. Chlorophyll traps light energy
and gives leaves and stems their green color.
Mitochondria and energy
Mitochondria are
membrane-bound
organelles in plant
and animal cells that
transform energy for
the cell.
Mitochondria and energy
A mitochondria, like the
endoplasmic reticulum,
has a highly folded
inner membrane.
Energy storing
molecules are produced
on inner folds.
Structures for Support and
Locomotion
Cells have a support structure called the
cytoskeleton within the cytoplasm. The
cytoskeleton is composed of microtubules
and microfilaments. Microtubules are thin,
hollow cylinders made of protein and
microfilaments are thin solid protein fibers.
Cilia and flagella
Some cell surfaces have cilia and flagella,
which are structures that aid in locomotion
or feeding. Cilia and flagella can be
distinguished by their structure and by the
nature of their action.
Cilia and
flagella
Cilia are short,
numerous, hair-like
projections that
move in a wavelike
motion.
Cilia
Cilia and
flagella
Flagella
Flagella are long
projections that move
in a whip-like motion.
Flagella and cilia are
the major means of
locomotion in
unicellular organisms.
All living cells must maintain a balance
regardless of internal and external
conditions. Survival depends on the
cell’s ability to maintain the proper
conditions within itself.
Why cells must control
materials
The plasma
membrane is the
boundary between
the cell and its
environment.
It is the plasma membrane’s job to:
• allow a steady supply of glucose, amino acids,
and lipids to come into the cell no matter what
the external conditions are.
• remove excess amounts of these nutrients when
levels get so high that they are harmful.
• allow waste and other products to leave the
cell.
This process of maintaining the cell’s
environment is called homeostasis.
Selective permeability is a process used to
maintain homeostasis in which the plasma
membrane allows some molecules into the
cell while keeping others out.
Plasma
Membrane
Water
Structure of the Plasma
Membrane
The plasma
membrane is
composed of two
layers of
phospholipids
back-to-back.
Phospholipids are lipids with a
phosphate attached to them.
The lipids in a
plasma membrane
have a glycerol
backbone, two
fatty acid chains,
and a phosphate
group.
Phosphate
Group
Glycerol
Backbone
Two Fatty
Acid
Chains
Makeup of the phospholipid
bilayer
The phosphate
group is critical for
the formation and
function of the
plasma
membrane.
Phosphate
Group
Makeup of the phospholipid
bilayer
The fluid mosaic
model describes
the plasma
membrane as a
flexible boundary
of a cell. The
phospholipids
move within the
membrane.
The Plasma Membrane
Other components of the
plasma membrane:
Cholesterol plays the important role of
preventing the fatty acid chains of the
phospholipids from sticking together.
Cholesterol
Molecule
Other components of the
plasma membrane:
Transport proteins allow needed
substances or waste materials to move
through the plasma membrane.
What happens in cells?
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Control of cell functions
Photosynthesis
Protein, lipid, carb. production
Digestion
Contraction
Secretion
Energy transformations
Protection
Support
Information transfer
Detect information
others
 There are many kinds of
cells
 All are specialized to do
different things
 Not all cells perform all
functions
 Cells are very
specialized
1.How did the invention of the microscope
impact society’s understanding of disease?
A. Scientists were able to view microorganisms
that were previously unknown.
B. Microscopes were invented after the
development of the cell theory.
C. It was once believed that viruses, not
bacteria, caused diseases.
D. Scientists could view membrane-bound
organelles of prokaryotes.
The answer is A. Before microscopes were
invented, people believed that curses and
supernatural spirits caused diseases.
Microscopes enabled scientists to view cells,
which led to the discovery that microorganisms
cause some diseases.
2. Which of the following uses a beam of light
and a series of lenses to magnify objects in
steps?
A. compound light microscope
B. scanning electron microscope
C. transmission electron microscope
D. simple light microscope
The answer is A. Most microscopes use at least
two convex lenses. Compound light microscopes
use a light beam and a series of lenses and can
magnify objects up to about 1500 times. Electron
microscopes use a beam of electrons and can
magnify structures up to 500 000 times.
3. What makes this cell eukaryotic?
A. Because it
has a cell wall.
B. Because it
contains DNA.
Nucleus
Nucleolus
C. Because it Chromosomes
has membranebound
organelles.
D. Because it
does not have
DNA.
Plasma
membrane
Organelles
The Answer is C. Eukaryotic cells contain
membrane-bound organelles that have specific
functions in the cell; prokaryotic cells do not.
Nucleus
Nucleolus
Chromosomes
Plasma
membrane
Organelles
4. Describe the
structure of the
plasma membrane.
The plasma membrane is composed of a
phospholipid bilayer, which has two layers of
phospholipids back-to-back. The polar heads of
phospholipid molecules contain phosphate
groups and face outward.
Phospholipid molecule
5. Why is the
phosphate
Polar head
group of a
(includes
phospholipid
phosphate
important to the Nonpolar
group)
plasma
tails (fatty
membrane?
acids)
When phospholipid
Phospholipid molecule
molecules form a
bilayer, the phosphate
Polar head
groups lie to the
(includes
outside. Because
phosphate
Nonpolar
phosphate groups are tails (fatty
group)
polar, they allow the acids)
cell membrane to
interact with its
watery (polar)
environments inside
and outside the cell.
6. Explain why the model of the plasma
membrane is called the fluid mosaic model.
It is fluid because the phospholipid molecules
move within the membrane. Proteins in the
membrane that move among the phospholipids
create the mosaic pattern.
7. What is the primary function of the cell wall?
A. act as selectively permeable membrane
B. provide support
C. control activity of organelles
D. acquire nutrients from environment
The answer is B. The
cell wall is an
inflexible, porous
barrier that provides
support but does not
select which
molecules can enter
the cell.
8. Describe the
control center of
a prokaryotic
cell.
Ribosomes
DNA
Plasma
membrane
Cell wall
Prokaryotic cells do not have true nuclei; their
DNA is not separated from the rest of the cell
by a membrane.
Plasma
Ribosomes
DNA
membrane
Cell wall
9. Which of the following structures is the site of
protein synthesis?
A. Golgi apparatus
B. Ribosome
C. Vacuole
D. Lysosome
The answer is B. Ribosomes are the sites
where the cell produces proteins according to
the directions of DNA. They can be attached to
the surface of the endoplasmic reticulum or
float freely in the cytoplasm.
10. What is the advantage of having numerous
folds in the ER?
A. It enables the ER to lie snugly against the
nucleolus.
B. It can create more vesicles in a smaller
space.
C. It can capture more light energy with more
folds.
D. A large amount of work can be done in a
small space.
The answer is D.
The ER is
arranged in a
series of folded
membranes,
which, if spread
out, would take
up tremendous
space.
11. What could you predict about a plant cell that
contains fewer chloroplasts than other plant cells?
A. It contains less chlorophyll.
B. It contains a greater number of plastids.
C. It will have an increased rate of light
energy capture.
D. It will appear darker green in color.
The answer is A.
Chloroplasts are among
the plant organelles
known as plastids and
contain the green
pigment chlorophyll.
Chlorophyll traps light
energy from the Sun
and gives leaves and
stems their green color.
12. A mutation results in the inner membranes of a
liver cell’s mitochondria being smooth, rather than
folded. Which of the following would you expect?
A. more efficient storage of
cellular energy
B. it can create more
vesicles in a smaller
space
C. decreased energy
available to the cell
D. fewer ribosomes
available for protein
synthesis
The answer is C.
Mitochondria transform
energy for the cell. A
highly folded inner
membrane provides a
greater surface area for
producing energystoring molecules.
12. Which of the following is a main idea of
the cell theory?
A. All organisms are composed of one cell.
B. The organelle is the basic unit structure and
organization of organisms.
C. All cells come from two parent cells.
D. All cells come from preexisting cells.
The answer is D.
The cell theory states
that a cell divides to
form two identical
cells.
13. In what type of cell would you find
chlorophyll?
A. prokaryote
B. animal
C. plant
D. fungus
The answer is C.
Chlorophyll is the
green pigment found
in the chloroplasts of
plant cells.
14. Which of these structures packs proteins
into membrane-bound structures?
A.
B.
C.
D.
Answer C depicts
the Golgi apparatus,
which sorts proteins
and packs them into
vesicles.
Cell wall
15. What is the
difference
between the cell
wall and the
plasma
membrane?
Inside
cell
Outside
cell
Plasma
membrane
The plasma membrane is a
flexible boundary between the
cell and its environment that
controls the supply of nutrients,
waste, and other products
entering and leaving the cell.
The cell wall is a rigid structure
found in plant cells, fungi,
bacteria and some protists that
provides support and protection
but does not select which
molecules can enter or leave the
cell.
Cell wall
Inside
cell
Outside
cell
Plasma
membrane
16. Which of the following organelles is
not bound by a membrane?
A. ribosome
B. Golgi apparatus
C. vacuole
D. lysosome
The answer is A.
Ribosomes are
simple structures
made of RNA and
protein and are not
bound by
membranes.
Ribosomes
17. Explain the
importance of
cholesterol to
the plasma
membrane.
Phospholipid
molecules
Cholesterol
molecule
Cholesterol
helps to
stabilize the
phospholipids
in the plasma
membrane by
preventing
their fatty acid
tails from
sticking
together.
Phospholipid
molecules
Cholesterol
molecule
18. In which of the following pairs are the
terms related?
A. cell wall – selective permeability
B. prokaryote – mitochondria
C. microfilaments – locomotion
D. plastid – storage
The answer is D.
Plastids are plant
organelles that are
used for storage.
19.Which of the following structures is
found in both plant and animal cells?
A. chloroplast
B. cell wall
C. mitochondrion
D. thylakoid membrane
The answer is C.
Mitochondria are the
organelles in both
plant and animal
cells that transform
energy for the cell.
20. __________ span the entire plasma
membrane and regulate which molecules enter
and leave the cell.
A. Transport proteins
B. Cholesterol molecules
C. Ribosomes
D. Microtubules
The answer is A. Transport proteins form the
selectively permeable membrane and move
needed substances or waste materials through
the plasma membrane.
21. Compare the cytoskeleton of a cell to the
skeleton of the human body.
The cytoskeleton and skeleton are similar in
that both form a framework. However, the
cytoskeleton is a constantly changing structure
with the ability to be disassembled in one
place and reassembled in another.
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The History of the Cell Theory
Anton van Leeuwenhoek - first person to
record observing with a microscope; 1600’s
Looked at water organisms
•Robert Hooke- 1600’s; used a microscope to study cork;
termed the word “cell”;
•Matthias Schleiden -1830’s; All plants made of cells
•Theodor Schwann – 1830’s; All animals made of cells
•Rudolph Virchow – all cells come from preexisting cells
•Rene Dutrochet- Cell is the basic functional unit of life