Biol 240 - UW - Midterm One || ANSWERS RATED 100%
CORRECT.
What is microbiology? correct answers The study of microbes examines how microbes
interact with humans, with food, and how they can be used by humans
Microbes correct answers Everything small that we might study as microbiologists. Viruses,
archea, eukaryotes, and bacteria
Microorganism correct answers Excluding viruses, inert particles don't adhere to the strict
definition of life so they are not included under the topic of microorganisms
Prokaryotic correct answers Before the nucleus. Bacteria and archaea, both are
microorganisms
Eukaryotic correct answers After/including the nucleus. Fungi, protazoa, and algae. Have
membrane bound organelles
Robert Hooke (1635-1703) correct answers Dutch philosopher, early microscopes allowed
first description of microbes: fruiting structures of "molds" (i.e., fungi). Made small spherical
glass lenses to make a compound microscope, two lenses working together to magnify
something and make it visible to the eye. He looked at an old belt and saw very very small
plants growing on the old leather. He published a book about these small things under the
microscope
Antonievan Leeuwenhoek (1632-1723) correct answers Made improvements in microscope
lens construction that allowed the first description of bacteria. The father of microbiology. He
looked at plaque on teeth
What would happen if there was no microbes left on earth? correct answers We would have a
slight disadvantage in digestion, and we might not feel right. We would be a kilogram lighter.
Without soil microbes we wouldn't be able to break down anything. Things wouldn't mold,
leaves wouldn't break down into the ground. Some food production will cease, bread won't
rise
Jo Handelsman correct answers Talked to Obama about the microorganisms in his body
How do heterotroph microbes get energy? correct answers Ingests pre-formed organic
molecules. Eats others, this is basic metabolism. Organic molecules are broken down by
microbes to harness chemical energy (ATP) by fermentation (when there is no oxygen) and
aerobic respiration in the presence of oxygen. Aerobic respiration produces more energy
How do autotroph microbes get energy? correct answers Produces organic molecules. Self-
sufficient like a plant, eats from the atmosphere. Can then be a food source for heterotrophs
Macromolecules in Microbial Cells - Proteins (Polypetides and Amino Acids) correct
answers These make up over 50% of what is inside of a cell
,Macromolecules in Microbial Cells - Nucleic Acids correct answers RNA makes up about
20% of the cell (90% ribosomal RNA and the other 10% is the other kinds of RNA). DNA
makes up about 5%.
Macromolecules in Microbial Cells - Lipids correct answers Makes up about 10% of what is
inside the cell. Form a critical physical boundary around the cell
Macromolecules in Microbial Cells - Polysaccharides (Sugars) correct answers Used for
structural support and energy storage. Makes up about 7% of the cell.
The Phylogenetic Tree (Three Groups) by Carl Woese correct answers Divided into three
domains based on ribosomal RNA sequences. Each of the three domains have important
commonalities and defining characteristics. Bacteria, Eukarya, and Archaea
Which microbial domain has membrane bound organelles and a nuclear membrane? correct
answers Eukarya
Which two microbial domains have similar plasma membranes? correct answers Eukarya and
Bacteria
Cell walls are found in many species. ___ almost all have cell walls made out of
proteoglycan, ___ almost all have cell walls made out of various materials, and ___have cell
walls in some species, made out of various materials. correct answers Bacteria, Archaea,
Eukarya
Which two microbial domains have a single type of polymerase? correct answers Bacteria
and Archaea. The archaeal polymerase is similar to that of the eukaryal RNA polymerase II
Which two microbial domains have histones? correct answers Eukarya and Archaea. Bacteria
do not have true histones, but they do have histone like proteins
Viruses correct answers Technically, viruses aren't considered "alive"because they don't
replicate outside of a host cell. They have little to no biochemical activity outside of a host
cell making them inert and nonreactive outside of a host cell
Stanley Miller and Harold Urey correct answers In the 1950s, a grad student and his mentor,
simulated the "spark" that might have started forming organic molecules from the primordial
soup
Requirements of Early Life correct answers Genetic information storage, the ability to
catalyze biochemical reactions, and a way of separating the cell interior from the external
environment. Chemical reactions have to occur within a capsulized space for life to start
Ribozymes correct answers RNA behaving like enzymes (reaction catalyst). Genetic
information storage. Self-replicating
Micelles correct answers May have been an early form of plasma membrane
Last Universal Common Ancestor (LUCA) by Carl Woese correct answers Occurred right at
the origin of life, 4 billion years ago. Features of LUCA are Membrane bound, ATP as
, chemical energy, DNA to RNA to protein, Eats CO2, Fixes N2, Anaerobe, and Thermophile
(lots of heat tolerance). How does it make its energy? Hydrogen (H2) dependant. Burns
hydrogen for its electrons, hydrogen oxidizer
What does LUCA do if they want to move around to other parts of the planet if you are stuck
to your source of electrons? correct answers Water! Follow water!
How to circumvent a scarcity of electron donors in a reducing environment? correct answers
Water is everywhere. If you can figure out how to split it open and get the electrons out of it
and dump them on to CO2 and fix that (change it into to something they can use and reuse)
into organic carbon. Using light energy we figured out how to split water and use oxygenic
photosynthesis.
Stromatolites correct answers Microbial fossil records exist, largely in fossilized
"stromatolites" (carbonate pedestals with photosynthetic microbial mat on top). They're in a
biofilm which protects them from oxygen. Stromatolites were present all across the world.
There are fossils of stromatolites on rock faces
Endosymbiotic Theory correct answers Primitive prokaryotic microbes ingested other
microbes, starting a symbiotic relationship, forming the first basic eukaryotes. Mitochondrion
and chloroplast
Louis Pasteur (1822-1895) correct answers Discovered that living organisms discriminate
between optical isomers (enzymes can recognize D and L isomers and pick the one they
want). He also explained biological nature of alcoholic fermentation. He developed vaccines
for anthrax, fowl cholera, and rabies. Introduced sanitization in hospitals. Developed
pasteurization (if you heat something and them cool it will last longer, this keeps dairy
products from going bad as quickly). Disproved spontaneous generation (in the late 1800s)
and developed methods for controlling growth
Which metabolism and organism was likely associated with LUCA? correct answers
Autotrophy and H2 Oxidizer
A new microorganism has histones and a single RNA polymerase that looks a lot like one
you might find in fungi. What is it? correct answers Archaea
Robert Koch correct answers Determined Bacillus anthracis was the cause of anthrax and
Mycobacterium was the cause of tuberculosis. He established basic rules for determining
which microbes caused which diseases (Koch's postulates)
Koch's Postulates can be used to show a specific microbe causes a specific disease. The cause
and effect are proven if correct answers The suspected microbe is identified in every person
with the disease, but not those without the illness
A pure culture of the suspected microbe is obtained
Experimental inoculation of the suspected microbe into a healthy test host causes the same
illness. Take the pure culture and put it into a healthy animal, if they show the symptoms of
the disease then you could be correct.
The suspected microbe is recovered from the experimentally inoculated host organism.
Lastly, you have to be able to re-extract the pure culture from the animal that you infected
