TCU Microbiology Lab Exam 1 Questions and
Answers 100% Pass
chemically defined (synthetic) media - ✔✔media composed of precisely defined chemicals
elements that all bacteria need - ✔✔carbon, nitrogen, phosphorus, sulfur, oxygen, and hydrogen
minimal media - ✔✔media that contains exact nutrients needed for growth and nothing extra
- media is useful b/c we know exactly what's in it, but few organisms are resourceful enough to survive
with only a few salts and sugars
complex media - ✔✔- it contains all the nutrients necessary for the microbes
- aka general purpose media, satisfies the nutritional requirements of bacteria with more stringent growth
requirements
- consists of mix of digests & extracts from plant or animal tissue
- nutrient rich but poorly defined with the exact nutrients unknown
- in lab we use complex media: tryptic soy media
enriched media - ✔✔complex media that contains additional "special" nutrients/additives that are not
commonly found in media
- least commonly used media
autoclave - ✔✔media is subjected to high-pressure steam at 121C at 15 lbs. of pressure to sterilize and
destroy any contaminants present
two major forms of media - ✔✔liquid and solid media
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- media solidifies by adding agar (1.5%)
- agar is inert and incapable of growing by itself
what temperature do most bacterial organisms grow at? - ✔✔37C (98.6F)
colony - ✔✔A population of cells arising from a bacterial cell group or from a group of attached bacterial
cells
colony forming units (cfu) - ✔✔estimate the approximate number of bacteria in a liquid broth culture
simple microscope - ✔✔contains a single magnifying lens and is similar to a magnifying lens
compound microscope - ✔✔consists of two singles lenses arranged one in front of the other so that the
second lens magnifies the image produced by the first
illuminator - ✔✔light emits from this
condenser - ✔✔light passes through this and concentrates the light and focuses the light onto the
specimen
parfocal - ✔✔property of a microscope which allows objectives to be changed with minimal or no
refocusing
total magnification - ✔✔objective magnification (4X, 10X, 40X, 100X) x ocular magnification (10X)
working distance - ✔✔distance between the objective and the object being viewed
depth of focus - ✔✔thickness of specimen that can be seen in focus at one time
resolving power - ✔✔the ability of the microscope to distinguish between two closely adjacent points;
measured in distance units
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