Download Electron Microscopes - Madison Public Schools

What do you think?
1. What do the muscles in your body use
when you run?
2. What thing goes through every part of your
body?
3. Where are the instructions
to what you are kept?
http://www.mynamesnotmommy.com/wpcontent/uploads/2013/05/questionmark.png
How can we see these?
1. Mitochondria in a cell
2. Red Blood cells
3. Nucleus of a cell
Microscopy - an introduction
• Microscopes are instruments
designed to produce magnified
visual or photographic images of
small objects.
The microscope must accomplish three tasks
1. produce a magnified image of the specimen
2. separate the details in the image,
3. render the details visible to the human eye or camera.
Scale
Microscope
One or more lenses that make an enlarged image of an
object.
Simple Microscope
• Light passes through only 1 lens.
• Example: magnifying glass
Compound Microscope
• Lets light pass through an object and then
through two or more lenses.
Stereoscopic Microscope
• Gives a three dimensional view of an
object. (Examples: insects and leaves)
• Used for dissections
Electron microscopes – use a beam of
electrons instead of a beam of light to
magnify the image
Electron Microscopes
• can achieve 3D images using electrons
The Scanning Electron Microscope
• produces a 3-dimensional image of
specimen’s surface features
spider
head of a butterfly
Scanning electron microscopy (SEM)
Types of specimens:
-Whole organisms
-Natural tissue surfaces
-Exposed tissue structure
What is this?
A flea magnified 50, 000 X
Transmission electron microscope (TEM)
– Provides for detailed study of the internal
ultrastructure of cells
– a beam of electrons
Longitudinal Cross section
of cilium
section of
cilium
is transmitted through
the specimen for
a 2D view
Figure 6.4 (b) cilia on rabbit lungs
1 µm
Transmission electron microscope
Chloroplast from a tobacco leaf
H1N1 virus
DENTIST’S DRILL
TOILET PAPER
HYPODERMIC NEEDLE
VELCRO
STAPLE THROUGH PAPER
BLACK WIDOW SPIDER CLAW
PORCUPINE QUILL
MASCARA BRUSH
BLACK FLY
MOSQUITO
CAT FLEA
MITE FEEDING
POLLEN GRAIN
ANT EYE
EYELASHES
What is the difference between a…
VIRUS
and
CELL?
E.coli bacterial cells
VIRUS
BACTERIA
- can’t live on its own- must
live inside another cell
- can exist on its own
- much smaller (20 – 400nm)
- larger (1000 nm = 1μm)
- none are beneficial
- some can be beneficial
(bacteria in gut)
- no cell wall, only a protein
coat
- outer cell wall
- cannot be killed by antibiotics
- are killed by antibiotics
Modified from http://cochrane.rockyview.ab.ca/Members/lynnmmoore/science-10/unit-3-cycling-of-matter-in-living-systems
/ch-7-the-basis-of-life/s10-lesson-1-cells-and-cell-theory/MICROSOPE%20TYPES%20PPT-1.2ppt.ppt/view