Transcript Two types of cells

CE L L S
Cell Discovery
How Did We Find Cells???
It took a long time for people to discover cells
and figure out what they were all about. We
needed sophisticated equipment
(microscopes!) to be able to see cells.
The First Microscopes
The early simple "microscopes“
were only magnifying glasses
that had one power, usually
about 6x - 10x.
One thing that was very
common and interesting to
look at, were fleas so these
early magnifiers called "flea
glasses".
s
Antony Van Leeuwenhoek
(1632-1723)
This Dutch scientist, became the first man to
make and use a real microscope.
He would grind a small glass ball into a lens with
a magnification of 270x, the finest known at
that time (other microscopes of the time were
lucky to achieve 50x magnification).
Leeuwenhoek, with his new improved
microscope, was able to see things that no man
had ever seen before like bacteria, yeast, blood
cells and many tiny animals swimming in a drop
of water. People did not realize that
magnification might reveal structures that had
never been seen before - the idea that all life
might be made up of tiny components unseen
by the unaided eye was simply not even
considered.
Robert Hooke (1665)
Hooke was an English scientist who
improved Leeuwenhoek ‘s microscope.
He looked at cork through a compound
microscope and observed tiny room-like
structures that reminded him of the "cells"
that monks lived in. Therefore these
structures became known as cells.
Matthias Schleiden (1838)
Schleiden was German Botanist the viewed
plants under a microscope and discovered that
plant are made of cells. He is considered to be
one of the co-founders of cell theory.
Theodor Schwann (1839)
Schwann was a German Biologist who viewed
animal parts under a microscope and
discovered that animals were also made up
of cells. He extended Schleiden's cell theory
about plants to animals, stating that ALL
living things are composed of cells.
Rudolph Virchow (1855)
Virchow was a German physician that
stated that all living cells come only from
other living cells.
Watch this!
Cell Theory
Every thing we now know about cells was
combined and called the
“cell theory”.
Cell Theory says that….
1. All living things are made of cells.
2. Cells are like the building blocks of all
living things.
3. New cells are only made from existing
cells.
Cells are the basic units of structure and
function in all living things
Cells come in all shapes and sizes!
There Are Two Types of Cells
Prokaryote Cells
And
Eukaryote Cells
Examples of the two types of cells are…
Prokaryotes
Archaebacteria
Eubacteria
Eukaryotes
Animal
Plant
These are two distinct types of
cells with STRUCTURAL
differences.
Cell Membrane
DNA
Cytoplasm
Nucleus
Prokaryote Cell
A simple single celled
organism.
Traits of Prokaryotes:
(pro-care-ee-ohts)
• They do not have a nucleus, and their genetic
material is not stored in the nucleus.
• They have only a few organelles.
• They are less complicated that eukaryotes.
• All bacteria are prokaryotes. Archaebacteria are
the oldest life forms and can only
survive in very harsh conditions.
Eubacteria are common and found
every where… even in you!
Bacteria may be small but they are powerful!
During the 14th century, 25% or ¼ of Europe was
killed by a bacteria called the Bubonic Plague,
also called Black Death. This bacteria was
spread through fleas and rodents.
But at the same time we need
bacteria to live!
1. Bacteria are decomposers and without them all
other organisms would not be able to survive.
2. We use bacteria in our digestive system to
help digest our food. There are approximately
ten times as many bacterial cells as human
cells in the human body!
3. We could not make cheese or yogurt without
bacteria.
Eukaryote Cell
A more complex cell.
Traits of Eukaryotes:
(you-care-ee-othts)
• They all have a nucleus where the genetic material
of the cell is stored.
• They have many organelles and are more complex
then prokaryotic cells.
• They can be single celled (just one cell) or can
make up more complex multi-cellular organisms.
• All plants, animals, fungi, and protists are
eukaryotic cells.
Animals
Fungi
All made of Eukaryotic cells!
Plants
Protist (single celled organisms)
Think – Pair - Share
What do you think is
the main difference
between a prokaryotic
cell and a eukaryotic
cell?
The nucleus!
PROkaryotic cells have NO
nucleus
&
EUKARYotic cells DO CARRY a
nucleus.
If there is time watch this introduction on cells!