Lecture 3A Microscopy and Staining Flashcards
representative microbiological organism of 1 meter
length of pork tapeworm, Taenia solium (1.8-8.0m)
metric units of length: decimeter
meaning of prefix: __
metric equivalent: __
- 1/10
- 0.1 m = 10^-1 m
metric units of length: centimeter
meaning of prefix: __
metric equivalent: __
representative microbiological application: __
- 1/100
- 0.01 m or 10^-2 m
- diameter of a mushroom cap (12cm)
metric units of length: millimeter
meaning of prefix: __
metric equivalent: __
representative microbiological application: __
- 1/1000
- 0.001 m or 10^-3 m
- diameter of a bacterial colony (2.3mm); length of a tick (5.7mm)
metric units of length: micrometer
meaning of prefix: __
metric equivalent: __
representative microbiological application: __
- 1/1,000,000
- 0.000001 m or 10^-6
- diameter of white blood cells (5um-25um)
metric units of length: nanometer
meaning of prefix: __
metric equivalent: __
representative microbiological application: __
- 1/1,000,000,000
- 0.000000001 or 10^-9
- diameter of poliovirus (25nm)
What can a scanning electron microscope (SEM) see?
10nm-1mm
- large protozoa (Euglena)
- human red blood cell
- chloroplast
- mitochondrion
- typical bacteria or archaea
- viruses
- ribosomes
What can a transmission electron microscope (TEM) see?
10nm-100um
- human red blood cell
- chloroplast
- mitochondrion
- typical bacteria or archaea
- viruses
- ribosomes
What can an atomic force microscope (AFM) see?
1nm-10nm
- proteins
- diameter of DNA
- amino acids
What can an unaided human eye see?
200um-above
What can a compound light microscope (LM) see?
200um-10mm
What can a scanning tunneling microscope (STM) see?
0.5nm-10nm
- proteins
- diameter of DNA
- amino acids
As the surface area to the volume ratio gets __ as the cell gets __
- smaller
- larger
if the cell grows beyond a certain limit, not enough material will be able to cross the __ fast enough to accommodate the increased cellular volume.
When this happens, the cell must divide into __ with a favorable surface area/volume ratios, or __.
- membrane
- smaller cells
- cease to function
General Principles of Microscopy
- wavelength of radiation
- magnification
- resolution
- contrast
the lower the nanometer, the __ the resolution
higher
the bigger the wavelength, the __ powerful it is
less
the weaker the radiation, the __ the resolution
lower
Electromagnetic spectrum
- radio waves and television
- microwave
- infrared
- visible light
- UV rays
- X rays
- Gamma rays
Electromagnetic spectrum: high-penetrability (also WC)
- X-rays
- Gamma rays
What have mutagenic-affects on DNA
UV light
Wavelength of radiowaves
10^3 m
Wavelength of microwave
10^-2 m
Wavelength of infrared
10^-4 m
Wavelength of visible light
5 x 10^-6 m
Wavelength of UV light
10^-6 m
Wavelength of X-ray
10^-8 m
Wavelength of Gamma-ray
10^-12 m
produces an image of the object upon which the microscope or magnifying glass is focused.
A simple microscope or magnifying glass (lens)
__ are bi-convex, meaning they are thicker at the center than at the periphery
Simple magnifier lenses
A __ allows us to see a considerably magnified image of our specimen. To continue magnifying an image beyond a certain point, however, serves little purpose, if it is not accompanied by an __.- Hoggs, 2005
- combination of two lens systems
- increase in detail