Chapter 2 Flashcards
The visualization of bacteria required the use of a compound ____ microscope.
Light
The visualization organisms that fall in the range of nm (nanometers) requires the use of a ____ microscope.
Electron
The visualization of microorganisms that fall in the range of mm (milli-) can be seen by _____
The naked eye.
Dimensions of MACROscopic organisms are usually given in ___ and ___.
Centimeters (cm), meters (m)
Dimensions of most bacteria fall between ___ and ___ in size.
1 um - 10 um (micrometers)
The method of spreading a small culture sample over a medium in a pattern that gradually this out the sample - resulting in isolated colonies is called the _____ method.
Streak plate method
With the ___ ___ technique, a small vol. of liquid, diluted sample is pipetted onto the surface of the medium and spread around evenly by a sterile tool (“hockey stick”)
Spread plate
Cells are pushed onto separate areas on the surface so that they can form individual colonies
In the __ __ technique, the sample is inoculated serially into a series of cooled, but still liquid agar tubes - so as to dilute the number of cells in each successive tube in the series.
Loop dilution (or, pour plate)
Loop dilution: Inoculated tubes are poured into sterile Petri dishes and are allowed to ____
Solidify (harden)
Media whose compositions are precisely chemically defined are termed ___
Defined (PURE organic and inorganic compounds)
___ media contain at least one ingredient that is NOT chemically definable
Complex media
Extracts/cells, tissues, secretions
3 Examples of Complex media
Blood, serum, meat EXTRACTS/INFUSIONS (non synthetic)
- Nutrient broth
- Blood agar
- MacConkey agar
Media is classified according to 3 properties:
- Physical state
- Chemical composition
- Functional type (purpose)
___ is a polysaccharide - that acts as a solidifying agent in microbiological media.
agar
Agar is ___ at room temperature
Solid
Agar ___ at the boiling temperature of water (100 degrees C)
Melts (liquifies)
Once liquified, agar does not resolidify until ______
It cools to 42C
Agar can be inoculated and poured in liquid form at temperatures that will not harm the handler: ___ C - ___ C
45 C - 50 C
T/F: Isolation of colonies usually requires a large number of cells to be inoculated over an expansive area of medium
False
Requires a small # of cells to be inoculated into a relatively large volume or over a large area of medium
The ____ ____ is a property used to classify media - and referees to the medium’s normal consistency.
Physical state
Three methods of ISOLATING media
- Streak plate
- Loop dilution (pour plate)
- Spread plate
An effective microscope should provide good (3):
- Magnification
- Resolution
- Contrast
Magnification occurs in (#) phase(s)
2 (two phases)
Magnification: The lens closest to the specimen is called the ___ lens
Objective lens
Forms the INITIAL IMAGE