Transcript The Cell Theory

The Cell Theory
Some Random Cell Facts
The average human being is composed
of around 100 Trillion individual cells!!!
 It would take as many as 50 cells to
cover the area of a dot on the letter “i”
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WOW!!!
Discovery of Cells
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1665- English Scientist, Robert Hooke, discovered
cells while looking at a thin slice of cork.
He described the cells as tiny boxes or a honeycomb
He thought that cells only existed in plants and fungi
Anton van Leuwenhoek
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1673- Used a handmade microscope to observe pond
scum & discovered single-celled organisms
He called them “animalcules”
He also observed blood cells from fish, birds, frogs,
dogs, and humans
 Therefore, it was known that cells are found in
animals as well as plants
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150-200 Year Gap???
Between the Hooke/Leuwenhoek discoveries
and the mid 19th century, very little cell
advancements were made.
 This is probably due to the widely accepted,
traditional belief in Spontaneous Generation.
 Examples:
-Mice from dirty clothes/corn husks
-Maggots from rotting meat
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19th Century Advancement
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Much doubt existed around Spontaneous Generation
Conclusively disproved by Louis Pasteur
Pasteur: Ummm, I
don’t think so!!!
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Development of Cell Theory
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1838- German Botanist, Matthias Schleiden,
concluded that all plant parts are made of cells
1839- German physiologist, Theodor Schwann,
who was a close friend of Schleiden, stated that
all animal tissues are composed of cells.
Development of Cell Theory
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1858- Rudolf Virchow, German physician,
after extensive study of cellular pathology,
concluded that cells must arise from
preexisting cells.
The Cell Theory Complete
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The 3 Basic Components of the Cell Theory
were now complete:
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1. All organisms are composed of one or more
cells. (Schleiden & Schwann)(1838-39)
2. The cell is the basic unit of life in all living
things. (Schleiden & Schwann)(1838-39)
3. All cells are produced by the division of
preexisting cells. (Virchow)(1858)
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Modern Cell Theory
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Modern Cell Theory contains 4 statements, in
addition to the original Cell Theory:
The cell contains hereditary information(DNA) which
is passed on from cell to cell during cell division.
 All cells are basically the same in chemical
composition and metabolic activities.
 All basic chemical & physiological functions are
carried out inside the cells.(movement, digestion,etc)
 Cell activity depends on the activities of sub-cellular
structures within the cell(organelles, nucleus, plasma
membrane)
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How Has The Cell Theory Been Used?
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The basic discovered truths about cells, listed
in the Cell Theory, are the basis for things
such as:
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Disease/Health/Medical Research and Cures(AIDS,
Cancer, Vaccines, Cloning, Stem Cell Research, etc.)
Some Parting Thoughts
It is amazing to think that the cells that make
up our bodies are just as alive as we are.
Humans are just an intricately designed
community of cells, which must work
together to survive.
 Cells, in my opinion, are one of the strongest
cases for intelligent design by our Creator
God!
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Eukaryotic Cells
 Eukaryotic
cells: HAS A
NUCLEUS!!
 All organelles are membranebound
 All other kingdoms than
bacteria
 Unicellular or multicellular
Prokaryotic Cells
 Prokaryotic
cells: CELLS WITH NO
NUCLEUS!!
 No membrane bound organelles
 BACTERIA!!!
 Great degree of diversity
 Unicellular
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Prokaryotic vs. Eukaryotic Cells
Prokaryotic cells
 No Nucleus
 No Organelles
 Cell Wall of peptidoglycan
 Binary Fission
 1 circular chromosome
Eukaryotic Cells
 Nucleus
 Organelles
 If cell wall, Cellulose or chitin
 Mitosis
 Linear chromosomes
What is a cell?
 What
is a cell?
 A cell is the basic unit of living
things.
 Some living things are composed of
only one cell and are called
UNICELLULAR organsims.
 Organisms that have many different
cells are called MULTICELLULAR
organisms.
Kingdoms and their
CellsAll living things have cells!!
1.
2.
3.
4.
5.
6.
Would viruses have cells?
6 kingdoms Of Living Things
Archeabacteria
Eubacteria
Protists
Fungus
Plants
Animals
Cells that build the organism
Cells that build the organism
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Every kingdom is made up of different
types of cells. Lets look at some
different cells.
Archeabacteria – simplest
organism(unicellular)
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Oldest Living Things on Earth! Found in
extreme environments: volcano vents,
hot springs, etc.
Eubacteria – more complex
than archae( unicellular)
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All other bacteria: like on your skin, in
your SI, yogurt, cheese, etc
Protists – more complex than
bacteria(unicellular)
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Unicellular kingdom found in water or
liquids only. Consumers and producers
Ameoba
euglena
stentor
Protists
These are protists called
diatoms that cause red tide.
Uses the oxygen out of the
water and kill all animals!!!
Fungus
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Kingdom of multi-cellular organisms
(except yeast). Mostly decomposers.
Athlete’s Foot
Mushroom
Yeast
Plants – producer for other
kingdoms
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4 organs of a plant
Root, stem, leaf, and flower
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Why would the root not be green?
Animals
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Kingdom of multicellular organisms that
are consumer
Bone cells
Blood cells
Animal cells
Skin cell
red and white blood cells
Skeletal
muscle
Cancer cells- out of control
cell growth!!
Breast cancer
bladder cancer
bone cancer
What is an organelle?
An organelle is a membranebound structure that carries out
specific activities for the cell.
You will need to know the following organelles
and their function:
Cell Membrane, Nucleus, Cytoplasm
,Mitochondria, Golgi Complex,
Ribosomes,Smooth Endoplasmic Reticulum
Rough Endoplasmic Reticulum, Cell Wall,
Chloroplast, Central Vacuole, Lysosome,
Microtubles, Microfilaments,
Nucleolus,Vesicles,Cytoskeleton,Centrioles
Organelles - Control Center
Nucleus
 Nucleolus
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Nucleus
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The control center of
the cell. It contains
the DNA code for the
cell coiled into
chromosomes.
 Cell
process: cell
division, protain
making, energy ,
etc
Nucleolus
 Organelle
in the
nucleus that is
the site to make
ribosomes.
 Cell process:
protein making
Organelles - Store, clean,
support
 Vacoules,
Vesicles,
cytoskeleton,
microtubules,
microfilaments,
centrioles,
lysosomes,
cytoplasm
Cytoplasm
(not an organelle
All organelles reside
(live and float around
in) the cytoplasm.
 Cell process:
 Cell division
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Lysosome
Breaks down
materials for
digestion.
 Contains special
enzymes for
digestion in the cell.
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Central Vacuole
(Plant Cell Only)
Most plant cells have
one large one.
 Filled w/ fluid.
 Helps maintains
turgor pressure and
shape of cell.
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Cytoskeleton
Network of proteins
that change to meet
the needs of the
cell.
 Microtubules
 Intermediate fibers
 Microfilaments
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Microtubules
Long hollow tubes
that gives the cell
shape and helps to
track the movement
of organelles. In
cell division,
microtubules pull
apart DNA.
 Process: Cell division
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Microfilaments
Small threads that
enable the cell to
divide and move.
They play an
important role in
muscle contractions.
 Cell process: cell
division
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Centrioles
Produces the
microtubules that
pull apart
chromosomes
during cell division
 Cell Process: cell
division
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Vesicles
Protein Building
Organelles:
ribsosome,
ER(smooth and
rough)
 Golgi appartatus
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Ribosomes
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Synthesizes proteins.
Present in the cytoplasm.
Present with Rough ER.
No membrane present.
Cell process: protein
making
Smooth Endoplasmic Reticulum
Transports materials
throughout the cell.
 Digests lipids.
 Cell process:
Produces proteins.
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QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Rough Endoplasmic Reticulum
Covered with
ribosomes.
 Cell process:
Produces proteins.
 Transports materials
throughout the cell.
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Golgi Complex
The protein
packaging and
transport center of
the cell.
 Has incoming and
outgoing vesicles.
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Cell Membrane
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Every cell is enclosed
by a cell membrane.
It controls the
passage of materials
in and out of the cell.
Energy Capture
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Organelles:
Mitochondria,
chloroplast
Mitochondria
This organelle
processes energy for
a cell. It makes
ATP.
 (ATP = energy)
 Involved in cellular
respiration.
 Cell process: cellular
respiration
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Chloroplast
(Plant Cell Only)
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Contains chlorophyll.
Makes plants green.
Uses light energy to
make ATP & sugars.
Photosynthesis takes
place here.
Cell process:
photosynthesis
Boundaries
Organelle:
 Cell membrane
 Nuclear membrane
 Cell wall
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Cell membrane
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Outer membrane
made of
phosolipids and
proteins that
controls traffic of
substances inside
and outside of the
cell.
Nuclear membrane
Controls movement
of materials to and
from the nucleus.
 Cell process: cell
division and protein
making
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Cell Wall
(Plant Cell Only)
Rigid and strong
wall.
 Protects and
maintains the shape
of the cell.
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