Shapes
What do you called a rod-shaped bacteria?
Bacillus.
Of the types of microscopes we discussed, this has the lowest level of magnification.
Stereoscope/dissecting microscope.
Bacteria are metabolically active but most are not dividing, as they are adjusting to the environment and preparing for growth.
Lag phase.
True or false: You can/should autoclave growth media.
True.
Which inoculation method allows you to isolate specific colonies of bacteria?
Streaking
What is the main difference between prokaryotic and eukaryotic cells?
Eukaryotic cells have membrane-bound organelles, such as a nucleus, mitochondria, and chloroplasts, while prokaryotes do not.
Others include: prokaryotes are much smaller than eukaryotes; prokaryotes have a smaller, singular circular chromosome compared to eukaryotes; prokaryotes do not have histones; prokaryotes can have plasmids.
What do you call circular-shaped bacteria?
Coccus.
This microscope uses a beam of electrons to scan the surface of a specimen, producing detailed 3D images
Scanning Electron Microscope (SEM)
These two phases of the bacterial growth curve see no net change in the number of living/viable cells?
Lag and stationary phases.
What do you call liquid growth media?
Broth
Name three characteristics that may need to be controlled in order to grow bacteria in culture.
pH, temperature, oxygen, nutrients, moisture
What are some differences between plant and animal cells?
Plant cells have a cell wall (and, subsequently, a rectangular shape), one or more large vacuoles, and chloroplasts.
Animal cells have none of the above, but they do have centrioles.
What do you call spiral-shaped bacteria?
Spirillum.
This type of microscope provides highest level of magnification possible, producing detailed 2D images by transmitting electrons through a thin specimen.
Transmission Electron Microscope (TEM)
During the log phase, bacteria may experience this kind of growth, where they double in number in a constant, exponential rate.
Exponential or logarithmic growth
What substance is used to make growth media solid?
Agarose (1-2%)
Which stain is used to differentiate between bacteria based on the presence / thickness of a cell wall? What colors are involved?
Gram Stain.
Pink = gram-negative; think cell wall
Purple = gram-positive; thick cell wall
What do you call a cluster of genes under the control of a single promoter? Is this level of genetic organization present in eukaryotes, prokaryotes, or both?
Operon; prokaryotes.
What prefix do you use to describe cells that grow in clusters?
Staphylo-
What is the total magnification of a compound light microscope when using the second objective lens?
10x * 40x = 400x
This factor is a key limitation during the stationary phase, as it leads to the cessation of bacterial growth.
Nutrient depletion.
Also, build up of waste products and lack of space.
What is the purpose of selective media?
Selective media allow only growth to a certain spectrum of organisms.
Example = Eosin-Methylene Blue (EMB) agar is used for Gram-Negative growth by inhibiting Gram-Positive.
These bacteria can survive equally well in oxygen-rich and oxygen-depleted environments by switching between aerobic respiration and fermentation.
Facultative (an)aerobes
Which cellular process involving mRNA happens in eukaryotes, but not prokaryotes?
RNA processing (introns removed; poly A tail and 5' guanosine cap added).
What word do you use to describe cells that grow groups of four?
Tetrad
This microscope uses fluorescent dyes or proteins to highlight specific structures, producing bright, colorful images against a dark background.
Confocal microscope
Some bacteria in the stationary and decline phases can adapt by entering a dormant state in response to unfavorable conditions, forming these highly resistant structures.
(Endo)spores.
What is the purpose of differential media?
Differential media (or indicator media) contain substances that lead colonies of certain organisms to take on a distinctive appearance, allowing for easy identification.
Example = blood agar causes some bacteria to produce enzymes that hemolyze red blood cells, allowing scientists to distinguish between hemolytic and nonhemolytic bacteria.
How do you label a Petri dish?
Label must include name, date, type of media, and type of organism. Label should be on the outer rim of the lid or bottom.
What are the differences between a virus and a bacterium?
Viruses are really tiny agents that infect cells, including animal cells, plants cells and bacteria. They can replicate only inside a living cell.
Bacteria, on the other hand, are single-celled microorganisms that can live and reproduce on their own (they are small but larger than viruses).