Chapter One: Section Two: Microscopes allow us to see inside the cell.
BEFORE, you learned
Some organisms are unicellular, and some are multicellular
A microscope is necessary to study most cells
The cell theory describes the cell as the fundamental unit of life
NOW, you will learn
About different types
of microscopes
About prokaryotic and
eukaryotic cells
How plant and animal
cells are similar and
different
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Think About
How small are cells?
o 1𝒎𝒊𝒄𝒓𝒐𝒎𝒆𝒕𝒆𝒓 1𝜇𝑚 =1
1,000,000𝑚𝑒𝑡𝑒𝑟
17,000 bacteria
cells lined up would
fit across a dime
Page 18
o How many of these cells might fit on your fingertip?
The Microscope is an Important Tool
Pages 18 - 19
In light microscopes, LENSES bend
the LIGHT to make objects appear
BIGGER than they are.
. . .
. . .
. … .. ..
Mixed Bacteria
as seen under a light
microscope
Modern Light
Microscopes can magnify
objects
up to 1000x!
The Microscope is an Important Tool
Pages 18 - 19
Cell samples are
treated with dyes
to make structures
in the cells easier
to see.
The Microscope is an Important Tool
Scanning Electron
Microscope (SEM) Transmission Electron
Microscope (TEM)
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Can produce images
as small as
0.00002 µm (micrometers)
In both SEM and TEM, tiny particles called ELECTRONS, not LIGHT are
used to produce images.
The Microscope is an Important Tool
SEM & TEM Light Microscope
Page 19
Electrons, not light
used to produce
images
Light used to
produce images
Used to see the
Details of the parts
of cells
Used to see some
Parts of the cells
CANNOT be used
to study LIVE cells
Allow scientists to
study Living
Cells
Used to
observe
Microbes
that can not
be seen with
just your
eyes
Page 19
Looking at Organisms with a SEM:
1) Cell samples must be coated in a heavy metal.
2) The electrons bounce off the coating and are read by a detector.
3) The detector produces a 3-D image of the surface.
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Looking at Organisms with a TEM:
1) Sample must be sliced extremely thin.
2) Electrons pass through a thin section.
3) Images appear 2-D.
Cells are Diverse
Page 20
Cell Membrane:
Encloses the inside
of each cell and
protects it.
Cytoplasm:
Gelatin-like
material inside
the cell
membrane.
Genetic Material:
Allows the cell to
reproduce and
function.
Cells are Diverse
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Genetic Information
PROKARYOTIC CELLS:
Genetic Information is
located in the
Cytoplasm
Cells are Diverse
Page 20
Genetic Information
EUKARYOTIC CELLS:
Genetic Information is
separated from the
cytoplasm by a membrane.
The ORGANELLE that contains
most of the genetic material
is called the NUCLEUS.
Plants and Animals Have Eukaryotic Cells
Plants have Cell Walls
A tough outer
covering that lies
just outside the cell
membrane.
Protects and
supports cell.
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Plants and Animals Have Eukaryotic Cells
Nucleus:
Usually the largest
organelle in the
cell.
Stores the
instructions a cell
needs to function.
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Structures that Process Information (Plants & Animals)
Page 23
Structures that Process Information (Plants & Animals)
Ribosomes: Use
information to build
important proteins.
Organelles that Provide Energy (Plants)
Page 23
Chloroplast: Energy
from sunlight is used
to make sugars.
Organelles that Provide Energy (Plants & Animals)
Page 23
Mitochondria:
Organelles
that use oxygen
to get energy
from processing
food.
Organelles that Process and Transport
(Plants & Animals)
Pages 23 - 24
Golgi Apparatus: Takes materials
made by the
Endoplasmic Reticulum and
finishes processing
them.
Endoplasmic Reticulum: Makes parts of
cell membrane and transports materials.
Organelles for Storage, Recycling, and Waste
Plant Cells: Vacuoles
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vacuole
Plant Cells: Vacuole
Animal Cells: Lysosomes
Organelles for Storage, Recycling, and Waste
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