Transcript Cells - Duplin County Schools

Microscopes and Cells
Cells
Dutch cloth merchant and amateur scientist
Anton van Leeuwenhoek
found microscopic creatures in standing water.
Using microscopes he made himself, Leeuwenhoek
drew what he saw in pond water, plant material, even
gunk scraped off his teeth.
He was the first to identify sperm and red blood cells.
Best Known for coining the
term “CELL”
As
“little room”
Robert Hooke
• Hooke's cell drawing — This drawing, published in 1667, shows
the cells Robert Hooke observed in a peice of cork wood that
he looked at under a microscope. Courtesy National Library of
Medicine.
CELL THEORY
Schwann
•
•
Schleiden
Virchow
All living things are made up of cells.
Cells are the basic units of structure
and function in living things.
• Living cells come only from other living
cells.
All Cells Are Not
Created Equal!
All Cells have different types and amounts of organelles.
The larger a cell becomes the more organelles it will need.
A big cell will need more nourishment than a little cell.
A larger cell would need to have more mitochondria to
process food into energy.
Unicellular and Multicellular Organisms
Eukaryote and Prokaryote Cell
Animal Cell and Plant Cell
Which are plant cells and which are animal cells?
Plant Cell and Animal Cell
Compound Light Microscope
• Total Magnification is
determined by
multiplying the
eyepiece power
(usually 10x) by the
objective lens in place.
• For example, a 10x
eyepiece and a 4x
objective yields a total
magnification of 40x
(40 power).
Why is the image in the microscope inverted ?
Preparing a Wet Mount
1. Place it on the glass slide so as to look
like (e). Place one drop of water on the
specimen.
2. Cover it with a clean cover slip.
3. Turn on the microscope and place the
slide on the stage; making sure the "e" is
facing the normal reading position.
4. Using the course focus and low power,
move the body tube down until the "e"
can be seen clearly.
Staining Cells
This picture was
taken before
staining, and it is
harder to see
» This
picture
was
taken
after
staining
Transmission
Electron Microscope
(TEM)
• Scanning Electron
Microscope (SEM)
TEM
Transmission
Electron
Microscopes
Use electrons
instead of light to
create an image.
The material
prepared must be
very thin and dead.
The beams of
electrons that pass
through it give the
viewer high
magnification and
resolution.
SEM
A Scanning Electron Microscope uses
electrons instead of light to create an image. These
microscopes produce three-dimensional images with
high resolution and magnification. They also have a
larger depth of focus. Specimens do not have to be
dead.
Bovine (cow) Pulmonary
Artery Endothelial Cell
Cancer Cell (Human)
Cedar Leaf
Stamen and Pollen 125X
Cedrus atlantica
200X
Animal Cell with mitochondria, ribosomes, chromatin, cytoplasm,
endoplasmic reticulum, nucleolus
TEM X 9,400
Liver Cell Nucleus and Nucleolus TEM X20,740
Nucleus and Nuclear Pores of Liver Cell (Animal Cell) TEM X 73,200.
Ribosome, cytoplasm, Chromatin, nuclear pores
Phospholipid Bilayer or Plasma
Membrane