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Microbiology 2060 Exam 1| Salt Lake Community College, Already Graded A
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Microbiology 2060 Exam 1| Salt Lake Community College, Already Graded A
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Evolutionary history of a group of organismsWhat is phylogeny?
What does microscopic mean? Not visible to the unaided eye
It is a complex community of one or more
microorganism species, typically forming as a slimy
coating attached to a surface because of the
production of an extrapolymeric substance (EPS)
What is a biofilm?
that attaches to a surface or at the interface
between surfaces (e.g., between air and water).
- In nature, biofilms are abundant and frequently
occupy complex niches within ecosystems
the distance between corresponding points on
adjacent waves
What is wavelength?
The height of each peak (or depth of each trough)
of a wavelength
What is amplitude?
occurs when a wave bounces off of a material. For example, a red piece of cloth may
What is reflection?
reflect red light to our eyes while absorbing other colors of light.
occurs when a material captures the energy of a light wave. In the case of glow-in-the-
What is absorbance? dark plastics, the energy from light can be absorbed and then later re-emitted as
another form of phosphorescence.
objects: the ability to tell that two separate points or objects are separate.
What is resolution? - low res appears fuzzy
- high res is sharp and clear
Transmission occurs when a wave travels through a material, like light through glass (the
What is transmittance?
process of transmission is called transmittance).
- Light waves can also interact with each other by
interference, creating complex patterns of motion.
-Dropping two pebbles into a puddle causes the
What is interference?
waves on the puddle’s surface to interact, creating
complex interference patterns. Light waves can
interact in the same way.
is perhaps the most important behavior exhibited by
light waves. Refraction occurs when light waves
change direction as they enter a new medium
(Figure 2.4). Different transparent materials transmit
What is refraction? light at different speeds; thus, light can change
speed when passing from one material to another.
This change in speed usually also causes a change
in direction (refraction), with the degree of change
dependent on the angle of the incoming light.
, Light that is emitted very quickly by the excited molecule as it gives up trapped energy
and returns to a more stable state.
What is fluorescence? - a Fluorescent microscope uses fluorescent chromophores called fluorochromes,
which are capable of absorbing energy from a light source and then emitting this
energy as visible light. Fluorochromes
- Detergents contain synthetic surfactant molecules with both polar and nonpolar
regions that have strong cleansing activity but are more soluble, even in hard water,
and, therefore, leave behind no soapy deposits.
- Anionic detergents, such as those used for laundry, have a negatively charged anion
What is catatonic? at one end attached to a long hydrophobic chain, whereas cationic detergents have a
positively charged cation instead.
- Cationic detergents include an important class of disinfectants and antiseptics called
the quaternary ammonium salts (quats), named for the characteristic quaternary
nitrogen atom that confers the positive charge (Figure 13.26).
- Detergents contain synthetic surfactant molecules with both polar and nonpolar
regions that have strong cleansing activity but are more soluble, even in hard water,
and, therefore, leave behind no soapy deposits.
- Anionic detergents, such as those used for laundry, have a negatively charged anion
What is anionic? at one end attached to a long hydrophobic chain, whereas cationic detergents have a
positively charged cation instead. Cationic detergents include an important class of
disinfectants and antiseptics called the quaternary ammonium salts (quats), named for
the characteristic quaternary nitrogen atom that confers the positive charge (Figure
13.26).
- In addition to fixation, staining is almost always applied to color certain features of a
specimen before examining it under a light microscope.
- Stains, or dyes, contain salts made up of a positive ion and a negative ion.
What is a chromophore? - Depending on the type of dye, the positive or the negative ion may be the
chromophore (the colored ion); the other, uncolored ion is called the counterion. If the
chromophore is the positively charged ion, the stain is classified as a basic dye; if the
negative ion is the chromophore, the stain is considered an acidic dye
a decolorizing agent is added to a gram stain, usually ethanol or an acetone/ethanol
solution. Cells that have thick peptidoglycan layers in their cell walls are much less
What is the decolorizer? affected by the decolorizing agent; they generally retain the crystal violet dye and
remain purple. However, the decolorizing agent more easily washes the dye out of
cells with thinner peptidoglycan layers, making them again colorless.
is a substance used to set or stabilize stains or dyes; in this case, Gram's iodine acts like
What is mordant? a trapping agent that complexes with the crystal violet, making the crystal violet-iodine
complex clump and stay contained in thick layers of peptidoglycan in the cell walls.
What is the primary stain? crystal violet
that disease was caused by the gods as punishment for sins, bad character, poverty,
What are early beliefs about disease?
family lines
What biblical practices were happening They were being isolated, which was the right thing to do in the absence of Abx
when people got sick?
Hippocrates was the first to do what is First to hypothesize that it was from natural causes in the environment or self instead
regards to disease? of supernatural forces
What did Thucydides contributed to He saw that during the Athenian plague soldiers who got sick and survived never got
microbiology? sick again. He saw immunity and only sent soldiers who had previous had the plague
He hypothesized that there were tiny disease causing agents, tiny little animals, in the
What did marcus terenius Varro contribute to
water and air that were causing disease - animal minuta
microbiology?
- side of street with sewer waste, saw way more illness than side of street without
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