Microbiology Exam-1
Which of the following diseases is (are) caused by prions?
All of the choices are correct.
Which of the following is (are) used by microorganisms to become resistant to a particular drug?
All of the choices are correct.
Which of the following is a function of pasteurization?
All of the choices are correct.
Which of the following is a useful mechanism of action for an antibacterial drug?
All of the choices are correct.
Which strategy can be used for regulation of metabolism?
All of the choices are correct.
What is the most compelling reason why DNA, rather than RNA, evolved to be the storage repository for genetic information in cellular life forms?
DNA molecules are more chemically stable than RNA molecules.
The most common pathway for conversion of glucose to pyruvate is
Embden-Meyerhoff.
__________ is a measure of the randomness or disorder of a system.
Entropy
Although similar in function, the eukaryotic ribosome is generally smaller and more complex than the prokaryotic ribosome.
F
Archaeal and Bacterial pili are identical in structure and function.
F
Viruses are not generally studied by microbiologists because they are not classified as living organisms.
F
Who is usually credited with the discovery of penicillin?
Fleming
Which group of microbes contains organisms necessary for production of wine and bread?
Fungi
Glyceraldehyde-3-phosphate and 3-phosphoglycerate are three-carbon molecules produced during the Calvin Cycle.(Video)
T
Many enzyme catalyzed reactions are freely reversible; however, some key steps require separate enzymes for the reverse step in order to provide for independent regulation of anabolic and catabolic pathways.
T
Methanogens may contribute to the greenhouse effect and global warming due to methane production.
T
Mordants increase the binding between a stain and specimen.
T
Nongrowing cells continuously degrade and resynthesize cellular molecules during a process known as cellular turnover.
T
Prokaryotes were once described based on structures that were present in eukaryotes, but absent in prokaryotes.
T
Some photosynthetic bacteria produce gas vacuoles that regulate their buoyancy but contain no lipid.
T
The Calvin Cycle functions to construct carbohydrates from carbon dioxide. (Video)
T
The major difference between the vacuoles of eukaryotes and the inclusion bodies of prokaryotes is that the former are membrane-bound, whereas the latter are not.
T
The majority of mitochondrial proteins are manufactured under the direction of the nuclear DNA by cytoplasmic ribosomes.
T
The use of compartmentation for the simultaneous but independent regulation of anabolic and catabolic pathways occurs generally in eukaryotes but not in prokaryotes.
T
The instrument that produces a bright image of the specimen against a dark background is called a (n) __________ microscope.
dark-field
Enzymes catalyze a reaction by
decreasing the activation energy of the reaction.
Amphipathic organic molecules that serve as disinfectants by disrupting membranes and denaturing proteins are called
detergents
The substantial reduction of the total population of microorganisms on inanimate objects and the destruction of potential pathogens is called
disinfection
The major site of cell membrane synthesis is the
endoplasmic reticulum.
The terms phototroph and chemotroph refer to an organism's source of
energy
Catalytic proteins are known as ___________ whereas catalytic RNA molecules are known as ____________
enzymes; ribozymes
The two most important alcohol germicides are __________ and __________.
ethanol;isopropanol
Cells with a relatively complex morphology that have a true membrane-delimited nucleus are called
eukaryotes.
Organisms that do not require oxygen for growth but grow better in its presence are called
facultative anaerobes.
An agent that specifically kills fungi but not other kinds of microorganisms is also known as a
fungicidal agent.
Proteins that are embedded within the cytoplasmic membrane and not easily extracted are called __________ proteins.
integral
Gamma radiation
is used to sterilize some food products.
Sterilization involves __________ all viable microorganisms.
killing OR removing
Enzymes needed to digest all types of macromolecules are found in
lysosomes.
A filamentous organelle comprised of tubulins with a diameter of 25 nm is called
microtubule.
A purine or pyrimidine that is attached to a sugar, either ribose or deoxyribose, is called a _______.
nucleoside
In bacterial and archaeal cells, the electron transport chain is located in the _________ whereas in eukaryotic cells, the electron transport chain is located in the ____________.
plasma membrane; inner mitochondrial membrane
All of the following processes are located within a membranous structure EXCEPT
protein synthesis (translation).
The nucleolus plays a major role in synthesis of
rRNA
The process of carbon dioxide fixation refers to
reduction of carbon dioxide and incorporation into organic molecules that are assimilated.
The __________ is a group of proteins needed for DNA synthesis that assembles at the origin of replication.
replisome
Microorganisms assimilate large amounts of all of the following except ______ into organic molecules.
sodium
The term used to describe bacteria that are shaped like curved rods is
vibrio
Development of drug resistance is encouraged by
widespread use of broad-spectrum drugs.
The Calvin Cycle uses ________, which are products of the light reactions of photosynthesis. (Video)
ATP and NADPH C
Quorum sensing
All of the choices are correct.
Which of the following can be used as electron acceptors during anaerobic respiration?
All of the choices are correct.
The net gain of ATP per molecule of glucose metabolized anaerobically via the Embden-Meyerhof pathway in prokaryotes is
2
The disinfectant of choice for municipal water supplies is __________.
Chlorine
Cells carry out three major types of work; which of the following involves energy for cell motility and the movement of structures within cells?
Mechanical work
Which of the following is not a phase of the Calvin-Benson Cycle?
Oxidation phase
Who of the following provided the evidence needed to discredit the concept of spontaneous generation?
Pasteur
Which of the following structures are external to both Bacterial and Archaeal cells?
Pili
The most notable difference between PrPC (normal protein) and PrPSc (prion protein) is
PrPc folds appropriately whereas PrPSc does not fold correctly.
What enzymes hydrolyze proteins, releasing amino acids?
Proteases
__________ are cyclic nitrogenous bases with two rings and pronounced aromatic properties.
Purines
Which molecule is believed to have preceded the other two during the evolution of life?
RNA
Which pathway(s) is used to fix carbon dioxide?
Reductive tricarboxylic pathway
The Calvin cycle begins by the attachment of CO2 to which of the following?(Video)
RuBP
Synthesis of complex molecules from simpler ones with the input of energy is called ______.
anabolism
Chemotherapeutic agents that are natural products of microorganisms are most specifically referred to as __________.
antibiotics
The term used to describe bacteria that are rod-shaped is
bacillus
Organisms that require increased pressure for optimum growth are called
barophilic.
Aminoglycoside antibiotics
bind to the 30S ribosomal subunit.
Enzymes function as catalysts by
bringing the substrates together at the active site, in effect concentrating them and bringing the substrates together at the active site correctly oriented for the reaction.
A(n) _______________ increases the rate of a reaction without being permanently altered by the reaction.
catalyst
The most important distinguishing feature of eukaryotes that is lacking in prokaryotes is
the division of the cell into compartments bounded by membranes.
Consider a biochemical pathway with five steps that lead to the production of product Q. If there is an abundance of product Q, the most efficient way to slow down the entire pathway would be to regulate _____________________.
the first enzyme in the pathway
The limitation on microbial growth rate at high nutrient levels is/are
the saturation of the transport proteins for nutrient uptake.
One hypothesis about the decline in cell numbers during death phase is that the cells aren't all dying but instead remain alive but unable to grow when cultured, at least temporarily. These are known as
viable but nonculturable cells.
