Cells
SB1. Students will analyze the nature of the relationships between structures and functions
in living cells.
a. Explain the role of cell organelles for both prokaryotic and eukaryotic cells, including the cell
membrane, in maintaining homeostasis and cell reproduction.
SB3. Students will derive the relationship between single-celled and multi-celled organisms
and the increasing complexity of systems
d. Compare and contrast viruses with living organisms.
22 Clicker Questions…..
Get Ready!
Cell Discovery
How did cells get their name?
Robert Hooke (1665)
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Looked at a piece of cork under his microscope
Looked like little chambers in a monastery
The monks lived in chambers called cells
Hooke called the chambers in the cork “cells”
Were, in fact, cell walls of dead plant cells
Cell Discovery
Who saw the first living cells?
van Leeuwenhoek (1678)
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•
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“Father of Microbiology”
Improved microscope design
First to observe and describe microorganisms
Called them “animalcules”
Scientific Method
What is the difference between a hypothesis, theory, and a law?
Hypothesis:
This is an educated guess based upon observation. It
is a rational explanation of a single event or phenomenon based upon
what is observed, but which has not been proved. Most hypotheses can
be supported or refuted by experimentation or continued observation.
Theory:
A theory is an explanation of a set of related observations or
events based upon proven hypotheses and verified multiple times by
detached groups of researchers. One scientist cannot create a theory;
he can only create a hypothesis.
(Example: Theory of Relativity…pertains to gravity, time, & space)
Law:
In general, both a scientific theory and a scientific law are
accepted to be true by the scientific community as a whole. But law
describes a single action where a theory explains an entire group of
related phenomena. (Example: Law of Gravity…pertains to gravity alone)
Cell Theory
developed by Schwann and Schleiden
(1835); Virchow (1855)
1. All living organisms are composed of one or more
cells.
2. Cells are the basic unit of structure and function in
all living organisms.
3. Cells arise only from previous existing cells, with
cells passing copies of their genetic material on to
their daughter cells.
Clicker Question #1
Who gave cells their name?
a.
b.
c.
d.
Charles Darwin
Robert Hooke
Albert Einstein
Gregor Mendel
Clicker Question #2
Which of the following best
describes a theory?
a. It is an idea
b. It is a statement based on an observation
c. It describes a single action in science and
is accepted by all scientists
d. It is a scientifically accepted explanation
based on a hypothesis that has been
verified by many scientists
Clicker Question #3
Which of the following statements is
supported by the Cell Theory to identify if an
amoeba is composed of a cell?
a. Amoebas have the ability to split to create
another genetically identical amoeba.
b. Amoebas can move and hunt for food.
c. Amoebas need oxygen.
d. Amoebas must eat.
Cell Membrane
What is the cell (plasma) membrane?
• A phospholipid bi-layer that separates the
inside of the cell from the outside environment
• It is semi-permeable, which means that only
certain substances can pass freely through
Cytoplasm
What is the cytoplasm?
• A thick gel-like solution of water, salts, and
proteins that fills the interior of cells
Nucleus
What is a nucleus?
• A distinct central organelle that contains the
cell’s genetic information in the form of DNA.
• Controls all of the cell’s activities
Basic Cell Types
What are the two basic types of cells?
1. Prokaryotic: Cells do NOT have a nucleus or organelles.
Example: ALL Bacteria…E. coli, Strep, & Salmonella
How to Remember “Trick”…
Pro has NO nucleus
Prokaryotes
• Have NO nucleus
• Have nucleoid (like a nucleus…but not a real one)
with DNA in a circular plasmid
• Have almost NO organelles
(but they DO have ribosomes)
REMEMBER….
Pro has NO nucleus
Basic Cell Types
What are the two basic types of cells?
2. Eukaryotic: Cells HAVE a nucleus and organelles.
Examples: Plants, animals, fungus…All other cells
How to Remember “Trick”…
Eu has TRUE nucleus
Eukaryotes
• Have a true/real nucleus
• Have many different organelles
REMEMBER….
Eu has TRUE nucleus
Clicker Question #4
If a cell has a nucleus, it is
considered a(n):
a.
b.
c.
d.
Prokaryote
Eukaryote
Plant
Animal
Clicker Question #5
If a cell does NOT have a
nucleus, it is considered a(n):
a.
b.
c.
d.
Prokaryote
Eukaryote
Plant
Animal
Clicker Question #6
Which of the following is an
example of an eukaryote?
a.
b.
c.
d.
a virus
Staphylococcus
a sunflower
bacteria
Clicker Question #7
Which of the following is an
example of a prokaryote?
a.
b.
c.
d.
mushrooms
Escherichia coli
an oak tree
humans
Cell Organelles
Cytoskeleton
Ribosome
Endoplasmic
Reticulum
Golgi
Apparatus
Lysosome
Function
More Info
Found in
Cytoskeleton
• Defined: Supporting network of protein fibers that
provide a framework for the cell within the cytoplasm
• Function: Aids in cell & organelle movement & support
• 2 substructures: Microtubules & Microfilaments
(euk only)
Cell Organelles
Function
Supporting
Cytoskeleton
network
Ribosome
Endoplasmic
Reticulum
Golgi
Apparatus
Lysosome
More Info
Found in
Microfilaments
&
Microtubules
Prokaryotes and
eukaryotes
Ribosome
• Defined: Simple cell organelle that helps
manufacture proteins.
• Function: Synthesizes/make proteins
Can be
found
attached to
E.R. or free
in the cell
Cell Organelles
Function
Supporting
Cytoskeleton
network
Ribosome
Endoplasmic
Reticulum
Golgi
Apparatus
Lysosome
Make
proteins
More Info
Found in
Microfilaments
&
Microtubules
Prokaryotes and
eukaryotes
Free &
attached
Prokaryotes and
eukaryotes
Endoplasmic Reticulum
• Defined: Highly folded membrane system in eukaryotic
cells that is the site for protein and lipid synthesis.
• Function: Rough ER – synthesizes proteins
Smooth ER – synthesizes lipids
Cell Organelles
Function
Supporting
Cytoskeleton
network
More Info
Microfilaments
&
Microtubules
Prokaryotes and
eukaryotes
Prokaryotes and
eukaryotes
Ribosome
Make
proteins
Free &
attached
Endoplasmic
Reticulum
Transport
system
Rough ER
Golgi
Apparatus
Lysosome
Found in
(ribosomes attached)
Smooth ER
(No ribosomes attached)
Eukaryotes
Golgi Apparatus
• Defined: Flattened stack of tubular membranes that
modifies, sorts, and packages proteins into vesicles and
transports them to another organelle or out of the cell.
• Function: Modifies and packages proteins
Cell Organelles
Function
Supporting
Cytoskeleton
network
More Info
Microfilaments
&
Microtubules
Prokaryotes and
eukaryotes
Prokaryotes and
eukaryotes
Ribosome
Make
proteins
Free &
attached
Endoplasmic
Reticulum
Transport
system
Rough ER
Golgi
Apparatus
Modifies &
packages
proteins
Lysosome
Found in
(ribosomes attached)
Smooth ER
Eukaryotes
(No ribosomes attached)
Create
lysosomes
Eukaryotes
Lysosome
• Defined: Vesicle produced by the Golgi that
uses enzymes to digest excess or worn-out
cellular substances.
• Function: Digests
Cell Organelles
Function
Supporting
Cytoskeleton
network
More Info
Found in
Microfilaments
&
Microtubules
Prokaryotes and
eukaryotes
Prokaryotes and
eukaryotes
Ribosomes
Make
proteins
Free &
attached
Endoplasmic
Reticulum
Transport
system
Rough ER
Golgi
Apparatus
Modifies &
packages
proteins
Create
lysosomes
Eukaryotes
Lysosomes
Digests food
& dead
organelles
Filled with
enzymes
Eukaryotes
(ribosomes attached)
Smooth ER
Eukaryotes
(No ribosomes attached)
Clicker Question #8
This organelle is composed of
microfilaments and micotubules:
a.
b.
c.
d.
Lysosome
Ribosome
Cytoskeleton
Endoplasmic reticulum
Clicker Question #9
This organelle synthesizes proteins:
a.
b.
c.
d.
Lysosome
Ribosome
Cytoskeleton
Endoplasmic reticulum
Clicker Question #10
This organelle modifies proteins:
a.
b.
c.
d.
Lysosome
Ribosome
Golgi Apparatus
Endoplasmic reticulum
Clicker Question #11
This organelle is filled with enzymes
for digestion purposes:
a.
b.
c.
d.
Lysosome
Ribosome
Golgi Apparatus
Endoplasmic reticulum
Mitochondrion
• Defined: Double membraned organelle that converts
fuel into energy (ATP) that is available to the rest of
the cell.
• Function: Converts food into energy = Cellular respiration
Cell Organelles
Function
Mitochondrion Converts food
into energy
Cellular Respiration
Chloroplast
Cell Wall
Vacuole
Cilia &
Flagella
More Info
Produces
ATP
Found in
Eukaryotes
Chloroplast
• Defined: Double-membraned organelle that captures
light energy & converts it to chemical energy (glucose)
through photosynthesis.
• Function: Converts light, H2O, & CO2 into food = Photosynthesis
Cell Organelles
Function
Converts food
Mitochondrion into energy
Cellular Respiration
Chloroplast
Makes food
from sunlight
Photosynthesis
Cell Wall
Vacuole
Cilia &
Flagella
More Info
Produces
ATP
Contains
chlorophyll
Found in
Eukaryotes
Plants
ONLY
Cell Wall
• Defined: A rigid barrier that surrounds the outside of
the plasma membrane
• Function: Provides support and protection
Organism
Cell Wall is
made of:
Plants
Cellulose
Bacteria Peptidoglycan
Fungi
Chitin
Cell Organelles
Function
Converts food
Mitochondrion into energy
Cellular Respiration
Chloroplast
Makes food
from sunlight
Photosynthesis
More Info
Found in
Produces
ATP
Eukaryotes
Contains
chlorophyll
Supports
&
NOT found
Cell Wall
protects in animals!
Vacuole
Cilia &
Flagella
Plants
ONLY
Plants
Bacteria
Fungi
Vacuole
• Defined: Vesicle for temporary storage of materials such
as food, water, enzymes, and wastes.
• Function: Storage (in all plants and fungi, some others)
Cell Organelles
Function
Converts food
Mitochondrion into energy
Cellular Respiration
Chloroplast
Makes food
from sunlight
Photosynthesis
More Info
Found in
Produces
ATP
Eukaryotes
Contains
chlorophyll
Supports
&
NOT found
Cell Wall
protects in animals!
Vacuole
Cilia &
Flagella
Stores water,
food, & waste
Very large
in plants
Plants
ONLY
Plants
Bacteria
Fungi
Some eukaryotes
and prokaryotes
Cilium & Flagellum
• Cilia: Hair-like projections that function in cell
movement or sensory
• Flagellum: Long tail-like projection with a
whip-like motion that helps a cell swim.
Flagella
Cell Organelles
Function
Converts food
Mitochondrion into energy
Cellular Respiration
Chloroplast
Makes food
from sunlight
Photosynthesis
More Info
Found in
Produces
ATP
Eukaryotes
Contains
chlorophyll
Supports
&
NOT found
Cell Wall
protects in animals!
Vacuole
Stores water,
food, & waste
Cilium &
Aids in
Flagellum movement
Very large
in plants
Cilia (many hairlike)
Flagella (whip like)
Plants
ONLY
Plants
Bacteria
Fungi
Some eukaryotes
and prokaryotes
Prokaryotes and
eukaryotes
Clicker Question #12
These are hair-like and aid cells in
swimming/locomotion:
a.
b.
c.
d.
Cilia
Flagella
Flagellum
Tails
Clicker Question #13
Photosynthesis occurs here:
a.
b.
c.
d.
Chloroplast
Mitochondria
Cell Wall
Vacuole
Clicker Question #14
These two organelles are NOT
found in animal cells:
a.
b.
c.
d.
Chloroplast & Mitochondria
Cilia & Vacuoles
Cell Wall & Chloroplast
Mitochondria & Vacuoles
Clicker Question #15
These are very large in plants
and provides support when
filled with water:
a.
b.
c.
d.
Chloroplast
Mitochondria
Cell Wall
Vacuole
Clicker Question #16
Which of the following has a
cell wall?
a.
b.
c.
d.
Mushroom
Sunflower
E. coli
All of the above
Endosymbiotic Theory
•
Endosymbiotic Theory proposes that
eukaryotic cells arose from living
communities formed by prokaryotic
organisms.
•
Endo- means inside
• -symbiotic means a relationship where
both partners benefit
Endosymbiotic Theory
•
Prokaryotes entered ancestral eukaryotes
•
Prokaryotes did NOT act as a parasite by infecting
the host (eukaryote)
•
Eukaryotes did NOT digest the prokaryotes
•
Instead, the smaller prokaryotes began LIVING
inside the larger cell – giving rise to eukaryotes
Evidence Supporting the
Endosymbiotic Theory
• 1st - Mitochondria & Chloroplasts have DNA
similar to bacterial DNA.
• 2nd – Mitochondria & Chloroplasts have
ribosomes whose size & structure resembles
those of bacteria.
• 3rd – Like bacteria, Mitochondria & Chloroplasts
reproduce by binary fission when the cells
containing them divide by mitosis.
Click Here For Animation Tutorial
Clicker Question #17
Which of the following summarizes the
Endosymbiotic Theory?
a. Mitochondria & chloroplasts in
eukaryotes were once prokaryotes
b. Ribosomes & lysosomes in eukaryotes
were once prokaryotes
c. Mitochondria & chloroplasts are now
found inside prokaryotes
d. None of the above
Clicker Question #18
Which of the following are true?
a. Mitochondria has DNA similar to
prokaryotes
b. Ribosomes in eukaryotes are similar to
prokaryotes
c. When mitochondria create more of
themselves, they divide similar to how
prokaryotes divide
d. All of the above
Viruses
• Virus comes from the Latin word for “poison”
• Viruses are particles of nucleic acid, protein, and in
some cases lipids, that can reproduce only by infecting
living cells.
• Viruses are so small that they can only be seen using
an electron microscope.
Flu Virus
Ebola Virus
AIDS Virus
Bacteriaphage
Viruses
• Viruses have NO organelles!
• A typical virus is composed of a core of either
DNA or RNA surrounded by a protein coat.
Common Cold Virus
Small Pox Virus
Polio Virus
Herpes Virus
Viruses
• A virus’s outer protein coat is
called its capsid.
• A capsid is an outer protein
coat that enables a virus to enter a
host cell.
• The capsid binds to the surface of
a cell and “tricks” the cell into
allowing it inside.
Viruses
• Once inside the cell, the viral genes take over.
• The cell transcribes (reads and copies) the
viral genes, putting the genetic program of the
virus into effect.
• And often times the virus destroys the host
cell
Viral Infection Animation
Viruses
Vaccine: A preparation
of a weakened or killed
pathogen, upon injection, stimulates antibody
production or cellular immunity against the pathogen
but is incapable of causing severe infection (sickness).
• A world wide vaccination program was able to
eliminate smallpox!
• Antibiotics NEVER cure viral infections!!...ONLY Bacteria
Click here to compare
size!
Small pox
Viruses
Bacteria
(cells)
• Reproduces on their own
• Has organelles
• Large in size
• Cell wall for protection
Both
• DNA or RNA
• Cause disease
• Must have host to reproduce
• Has NO organelles
• Extremely small in size
• Capsid for protection
Clicker Question #19
Which of the following statements is
true about viruses?
a.
b.
c.
d.
Viruses do not have DNA
Viruses must have a host to reproduce
Antibiotics kill viruses
Viruses have organelles
Clicker Question #20
Which of the following is the
smallest?
a. White blood cell
b. Pollen
c. Bacteria
d. Virus
Clicker Question #21
Which of the following do viruses
NOT have?
a. Organelles
b. Capsid
c. Genetic material
d. They have all of the above
Clicker Question #22
DNA is located here:
a.
b.
c.
d.
Chloroplast
Nucleus
Lysosomes
Vacuoles
The End
Answers
1. B
2. D
3. A
4. B
5. A
6. C
7. B
8. C
9. B
10. C
11. A
12. A
13. C
14. D
15. B
16. D
17. A
18. D
19. B
20. D
21. A
22. B