Transcript Pro vs Eukaryotic

Chapter 7:
Cell Structure and Function
Cell Theory, Exploring the Cell, and
Prokaryotes vs. Eukaryotes
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Created by Amy Simcik
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Bell Work
Raise your hand if you recognize the following
names, terms and/or phrases….
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Objectives & Standards
•What invention led to the formation of the cell theory?
•What is the cell theory, and what evidence supports it?
•How do prokaryotic and eukaryotic cells
compare/contrast with each other?
•How are animal and plant cells alike and different?
Standards
SOL Bio.2a –students will investigate and understand then cell theory and evidence supporting the cell theory.
SOL Bio.4a – students will investigate and understand characteristics of prokaryotic and eukaryotic cells
SOL Bio.4b – students will investigate and understand basic cell structures and functions including diversity and variation
of eukaryotic cells; cell structure and function
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Microscopes…back in the day
In the mid-1600
scientists began using an early
compound microscope, like this
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How did the invention of
the magnifying lens and
light microscope led to the
accumulation of our
knowledge of the nature of
cells?
Lets find out from the
“Cell Theory Theater”
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Cell Theory
Theater
Shhhhhhh! No talking please!
Take notes on your worksheet
but DO NOT interrupt the actors!
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Robert Hooke
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In summary…
Hooke coined
In 1665, Robert ______
the term “cells” because his
observations of a thin slice of
cork looked like rooms at the
______
monastery to him under his
microscope.
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Anton van
Leeuwenhoek
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In summary…
Anton van Leeuwenhoeke was the
first to view living things in a
pond water in
sample of _______
1674. His observations are now
called ________________.
micro-organisms
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Fast Forward
164 years…
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Matthias Schleiden
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In summary…
In 1838, Mathias Schleiden, a
German _________,
botanist concluded
that plants are composed
cells
_________.
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Theodor Schwann
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In summary…
Schwann
In 1839, Theodor _____________,
a German biologist concluded
that all ________
animals are made of
cells.
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Rudolph Virchow
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In summary…
In 1855, Rudolph _______,
Virchow often
referred to as the “father of
pathology because he made
modern_________,”
many medical advances about diseases.
new cells could be
He concluded that ____
produced only from __________cells.
preexisting
(Therefore the previous idea of
spontaneous generation was disproved)
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The End
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Scientists Summary
Answer the “In conclusion…”
question on your interactive
notes now that summarizes
the scientists’ findings.
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The Traditional Cell Theory Tenets (beliefs):
a.) All living things are composed of one or more
cells that come from other cells by the process of
cell reproduction
b.) Cells are the basic units of structure and
function in living things
c.) cells contain specialized structures and
perform functions necessary for life
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Microscope Advances
Optical microscope
Looking at passport for authenticity
Light microscope
Compound
microscope
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Electron microscope
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Light microscope vs. Electron microscope
EMs show details
that are 1000 times
smaller than light
microscopes can
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Types of Electron Microscopes
Transmission electron microscopes (TEMs)
- beams of electrons can only pass through thin samples, so cells
and tissues must be cut into ultrathin slices first, then examined
under the microscope.
Scanning electron microscopes
(SEMs)
- pencil-like beam of electrons
scanned over the specimen’s
surface; 3-D images produced (no
cutting) but only non-living
preserved cells and tissues can be
visualized
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1990s – Scanning Probe Microscopes
-Trace the surfaces of samples with a fine probe
-Can operate in ordinary air and even show samples in a solution
-Can view DNA, proteins and other biological structures.
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Thanks to microscopes…
Thanks to scientific advances in microscopes,
scientists were able to study cells at a much
deeper level than before.
Well then, let’s learn
more about cells!
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Thanks to microscopes…
Did you get the notes
about microscopes?
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As a result of additional study
and the integration of studies of
cell life functions, a Modern Cell
Theory has been developed
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IN ADDITION to the traditional tenants:
a. energy flow (metabolism and
biochemistry) occurs within cells
b. cells contain hereditary information
(DNA) that is passed from cell to cell
during cell division
c. all cells are basically the same in
chemical composition in organisms of
similar species.
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Let’s Learn About the Two
Types of Cells
What is the difference
between a prokaryote and a
eukaryote?
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What are Prokaryotes?
• Prokaryotes are the simplest life forms
exhibiting cellular structure, and were Earth’s
first cells.
• Two major forms
(kingdoms):
Eubacteria and
Archaebacteria
Example: Bacteria
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Prokaryotes live in many environments
• Prokaryotes are the Earth’s most abundant
inhabitants. They can survive in a wide range
of environments and obtain energy in a
variety of ways.
• Ex. Deep ocean
volcano
hot springs
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Prokaryotes are simple
• They have no nucleus, and no membranebound organelles
• They may have flagella or cilia for movement
• As a single-celled organism, it has to conduct
all life processes itself.
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How did eukaryotes come about?
• Eukaryotes arose
from prokaryotes
• They developed
into larger, more
complex organisms
• Includes plants,
animals, fungi &
protists
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Prokaryotes and Eukaryotes
ALL cells have two characteristics in common:
1. surrounded by a barrier (cell membrane)
2. At some point in their lives, they contain DNA
3. contain cytoplasm and ribosomes
Two major differences:
Prokaryotes
Eukaryotes
NO nucleus; no
membrane-bound
organelles
Have a nucleus and
membrane-bound
organelles
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Prokaryotes
Eukaryotes
Simplest life forms
Earth’s first cells
Cytoplasm
Most abundant inhabitants
No nucleus; no membranebound organelles
May have flagella or cilia
for movement
2 Major forms: Eubacteria
& Archaebacteria
Ex. bacteria
ribosomes
Cell
membrane
DNA
Larger & complex;
Includes plants,
animals, fungi &
protists
Great variety: singlecelled to multi-cellular
organisms
Contain membranebound organelles
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Eukaryotic Cells
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Eukaryotic Cells: Plant & Animal Cells
I wonder how That’s
many a good question because
we look
differences there
are different, but I think we
between planthave
and a lot of the same parts!
But don’t forget that fungi and
animal cells?
protists are eukaryotes too!
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Plant
Animal
Cell membrane
Cells
Golgi Apparatus
Many large
Small
Mitochondria
vacuoles
vacuole
Nucleolus
Nuclear Envelope,
Cell Wall
Nucleus
Centrioles
Ribosomes
Chloroplast Endoplasmic Reticulum
Cells
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Eukaryotic Cells: Plant & Animal Cells
Wow, we have more things in
common than I thought! We
might look a lot different on the
outside, but when we are put
under a microscope…
…we have a lot of
the same
organelles!
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What came first?
Put items in order of their discovery
a.
b.
c.
d.
Cell theory
Invention of microscope
DNA observation
Observation of first cell
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Scripts for Students to read during
Cell Theory Theater
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1. Robert Hooke
Well hello there! My name is Robert Hooke. I was born in 1635 in England. Like many folk, I
know what it is like to be poor; not having enough money to buy food, never mind go out
and enjoy myself in the local pubs at night. As a young man I loved science! I had lots of
questions about science, but without any proof, nobody would pay me for my ideas.
Due to my passion to discover and create… not that I am bragging or anything… I left behind
many contributions to science from physics and astronomy, to chemistry, biology, and
geology, to architecture, oh! and don’t forget about naval technology.
Some of my inventions… (pause) maybe you have heard of some… include the telescope, the
early microscope, an early prototype of the respirator for breathing under water; and a
balance spring found in watches and clocks. I also invented equations for laws of physics
and instruments related to studying the weather, such as the barometer, sometimes on my
own and sometimes with other scientists. Needless to say, by the time my inventions were
finally being recognized and used by others, (smile) I did not have to worry about money any
more.
To summarize a lot of my findings, I wrote a book which included some extremely detailed
drawings of the flea, as you see here (point to board). One important finding was about
what I saw in a piece of cork when I put it under my microscope. I saw thousands of tiny,
empty chambers which looked like rooms I had seen in a monastery…you know… where
monks live. Well, these rooms were called cells so I decided to use the same word to
describe the small units that make up living things. Scientists after me did much more
research about these ‘cells.’
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(Sit down at your seat)
2. Anton van Leeuwenhoeke
Pronounced:“An-tony van Lay-ven-hook”
Good day! My name is Anton van Leeuwenhoeke. I was born in Holland in 1632. I
began working as a tradesman, just as my parents were. They made baskets and
some family members even made beer. I decided to work on making linens at first.
I then decided to focus on studying science, specifically working on understanding
the microscope. I made my own version of a microscope as you see here.
I was curious about what was around us that I could not see with my eye. I took a
sample of pond water, used my microscope and noticed many little creatures. I
called them “animal-cules.” People after me apparently did not like this name so
they called them single-celled organisms, which we now call micro-organisms.
After exploring pond water I was curious about other microscopic things. I was the
first to record microscopic documentation of muscle fibers, bacteria, and blood
vessels. Because of my hard work and my discoveries, people called me the
“Father of Microbiology.”
The study of cells did not stop here. More scientists came after me and further
developed my findings.
(Sit down at your seat)
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3. Matthias Schleiden
Pronounced “Ma-thigh-as Sch-leigh-den”
Hello! My name is Matthias Schleiden, and I was born in Germany in 1804. I first
studied law when I was in my twenties. After five years of being a lawyer and got
bored, so I decided to switch careers and become a botanist because I loved plants!
Not only did I study botany, I became a professor at a university and taught about
botany. While teaching was fun, I still was curious about plants, so I did research
on my own as well. I enjoyed learning new things about plants that were not yet
explained or discovered.
Seven years passed by and I decided to share my findings from my research with other
scientists. In 1838 I concluded that the different parts of plants are composed of
cells. This finding became very important in the explanation of cells, known as the
cell theory.
My friend, Rudolph Virchow, who you will hear from soon, also had a part in the cell
theory with me.
(Stand off to the side of the room. Get ready to jump in and say a line WITH Theodor
Schwann when he starts to say:)
“I can’t take all the credit, but in 1839, Matthias Schleiden and I developed the cell
theory, where we said…
(Say together) All living things are composed of cells, and cell products are
reproduced.
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4. Theodor Schwann
Hello, and good day to all of you. My name is Theodor Schwann, and I was born in 1810 in
Germany. I studied biology and also was interested in cells. Unlike my friend Matthias
Schleiden (Ma-theigh-as Sch-leigh-den), I studied animal cells. I realized that animal cells
had different properties than the plant cells that he was studying.
We were having dinner one fine evening when we started to discuss our work with cells and we
then realized that instead of competing with each other, if we put our ideas together about
plant and animal cells, our research made more sense. Both of us noticed that nuclei were
in the cells we studied.
I had a particular interest in figuring out how digestion worked and discovered enzymes that
ultimately are responsible for digestion. I discovered other muscle cells found in the
esophagus which, not to brag, but are named after me.
Now, I can’t take all the credit, but in 1839, Matthias Schleiden and I developed the cell
theory, where we said… (WAIT FOR MATTHAIS SCHLEIDEN TO STAND NEXT TO YOU, then
say together) “All living things are composed of cells, and cell products are reproduced.”
(Look at the other student and say…)
Ah, thank you for reliving that moment with me Matthias!
(Look back at class) Together we both recognized that membranes, nuclei and cell bodies were
common features found in animal and plant cells.
Another scientist decided to do more research and add to our findings…
(Walk back to your seat)
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5. Rudolph Virchow
Hello there! Like many of you, I have a very long name, which is Rudolph Ludwig Karl Virchow,
however I normally just go by Rudolf Virchow. I was born in 1821 in Germany. I too decided
to try out many careers ranging from anthropology, pathology, history, biology and even
politics.
Despite my many career paths, I am best known for my advances in medicine and because of
this, people decided to call me the “father of modern pathology.” If you were not sure,
pathology means the study and diagnosis of disease.
(Deep breath and smile) But back to my most famous discovery…
I looked at the findings of Theodor Schwann and also the findings of another scientist and
decided to take their research a step further.
(Act like you are about to tell a secret…)
Ok, so between you and me, I kind of stole my friend’s ideas and beat him to publishing the
findings that said that every cell originates from another existing cell like it, (pause) but let’s
keep that between you and me. Oh, and if you were wondering, we are not friends anymore
after he found out what I did.
What is important is that I… (little laugh) …concluded that new cells could be produced only
from the division of existing cells. So, thanks to me, Theodor Schwann and Matthias
Schleiden (Ma-thigh-as Sch-leigh-den), we came up with the cell theory!
(Take a bow, and then take your seat)
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Works cited:
http://www.ourstory.com/thread.html?t=344670
www.wikipedia.com
Miller & Levine Biology text
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