HW CH-11
An anaerobic chemoorganotroph that uses glucose for energy and pyruvate as its terminal electron acceptor is performing ______.
fermentation
Members of the Gram-negative genera Aquifex and Hydrogenobacter are hydrogen-oxidizing bacteria. An example of their metabolism involves using ______.
hydrogen as a source of energy and oxygen as a terminal electron acceptor, forming water
Extreme thermophiles are found near ______
hydrothermal vents hot springs volcanic vents
Enterobacteriaceae get their name because they reside in the ______ tract of humans and animals.
intestinal
A diverse group of Gram-negative bacteria that obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrate are known as
nitrifiers
Many cyanobacteria can convert nitrogen gas (N2) to ammonia, which is a process called ______.
nitrogen fixation
The purpose of storage granules produced by some bacteria is to store ______.
nutrients
Aerobic chemoorganotrophs gain energy via the _______, using O2 as a terminal electron acceptor.
oxidation of organic compounds
As a group, chemolithotrophs ______ to obtain energy.
oxidize reduced inorganic chemicals such as hydrogen gas
Aerobic chemolithotrophs obtain energy by oxidizing reduced inorganic chemicals, using ____ as a terminal electron acceptor.
oxygen (O2)
The _____ bacteria have projections called prosthecae, which are extensions of the cytoplasm and cell wall that increase the surface area to facilitate absorption of nutrients.
prosthecate
The purpose of the sheath in sheathed bacteria is for ______.
protection
By definition, obligate intracellular parasites cannot ______.
replicate outside of a host cell
Staphylococcus epidermidis is part of the normal microbiota of the ___
skin
A group of Gram-negative bacteria has a spiral shape and a unique motility mechanism that allows them to move through thick, viscous substances. This group is called the .
spirochetes
The motile cells found in sheathed bacteria are called ______ cells, and these exit through the end of the sheath.
swarmer
Scientists are interested in studying the growth of extreme ,____ archaea that grow near volcanic vents and fissures because these conditions are thought to mimic early earth's environment.
thermophiles
Bacteria that oxidize sulfur are Gram-negative rods or spirals that ______.
use sulfur compounds as an energy source and oxygen as a terminal electron acceptor
_____ species are Gram-negative curved rods that are highly motile and prey on other Gram-negative rods by boring a hole in their cell wall.
Bdellovibrio
A group of bacteria called green bacteria are ______.
Gram-negative
Members of the family Enterobacteriaceae are _______.
Gram-negative rods
Spirochetes are bacteria that are ______ and possess a unique mechanism of _______.
Gram-negative; motility
Like the green and purple bacteria, members of the genus Heliobacterium are also examples of anoxygenic phototrophs. They are ______ bacteria related to members of the genus Clostridium.
Gram-positive endospore-forming rod-shaped
During photosynthesis, anoxygenic phototrophs use _______ as a source of electrons to make reducing power.
H2S
Prokaryotes that grow well in an environment that contains 32% NaCl would be called extreme
Halophiles
Aside from green and purple bacteria, Gram-positive endospore forming rods of the genus ______ are also anoxygenic phototrophs.
Heliobacterium
A reason why environments that are routinely exposed to O2 can support anaerobic growth is that ______.
O2-consuming organisms depletes the oxygen levels
An organism that cannot reproduce outside of a host cell is termed an ___
Obligate intracellular parasites
Chemoorganotrophs oxidize ____ compounds such as glucose to obtain energy.
Organic
Obligate aerobes obtain energy using ___ exclusively; none of them can ferment.
RESPIRATION
Which of the following genera of organisms forms a beneficial symbiotic relationship with plants?
Rhizobium
Organisms that form storage granules include ______.
Spirillum Thiomargarita Thioploca
Which of the following bacteria is typically a harmless resident of the skin?
Staphylococcus epidermidis
Staphylococcus epidermidis is part of the normal microbiota of the
The skin
Which of the following were likely the earliest photosynthesizing organisms?
anoxygenic phototrophs
An organism found in an environment that is very hot and acidic is most likely a member of the domain .
archaea
Most of the anaerobic chemolithotrophs that have been discovered are members of what domain?
archaea
Cyanobacteria as a group are capable of ______.
both photosynthesis and nitrogen fixation
The earliest oxygenic phototrophs probably belonged to a group of bacteria called the
cyanobacteria
The study of the various adaptations prokaryotes use to survive terrestrial and aquatic environments is called
ecophysiology
Of the various types of dormant cells, the ______ is the most resistant to environmental extremes.
endospore
How do obligate aerobes obtain energy?
using respiration only
Oxygenic phototrophs use ______ as a source of electrons for reducing power, generating O2.
water
______ species are Gram-negative, strictly anaerobic, make up about a third of the bacteria in fecal matter in humans, and are associated with abscesses and bloodstream infections.
Bacteroides
I say: "Gram-negative bacteria, that are typically kidney-bean-shaped cocci in pairs. You say:
Neisseria
Chemoorganotrophs that perform ______ often use sulfur or sulfate as a terminal electron acceptor.
anaerobic respiration
An organism that requires a minimum of 9% NaCl would be called an ______.
extreme halophile
The green bacteria are Gram- _____ organisms that are typically green or brownish in color.
negative
Ecophysiology is the study of the ______.
physiological mechanisms bacteria and archaea use to live in terrestrial and aquatic environments
Prosthecate bacteria form projections called prosthecae, which are extensions of the cytoplasm and cell wall. These prosthecae ______.
facilitate absorption of nutrients
Which of the following correctly describe relationships between genera of bacteria and their means for obtaining nutrients from plants?
-Agrobacterium species are plant pathogens that cause tumor-like growths. -Rhizobium species form a mutually beneficial relationship with certain types of plants.
Hydrogen-oxidizing bacteria such as Aquifex and Hydrogenobacter are ______.
-Gram-negative -obligate chemolithotrophs -thermophilic
The cells of species in the genus Neisseria are ______.
-Gram-negative -typically found in pairs -cocci
Nitrifiers can be described as bacteria that ______.
-are Gram-negative -obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrite
How do aerobic chemoorganotrophs obtain their energy?
-by using O2 as a terminal electron acceptor -by oxidizing organic compounds
As a group, anaerobic chemoorganotrophs ______.
-can obtain energy via fermentation -produce ATP via substrate level phosphorylation
Sulfur-oxidizing bacteria ______.
-can use hydrogen sulfide or thiosulfate as an energy source -can sometimes grow in filaments
The normal habitat of Bacteroides species in humans includes the ______.
-genital tract -mouth -intestines
In a healthy individual, anaerobes can regularly be found on and in the ______.
-intestinal tract -skin -oral cavity
Bdellovibrio species ______.
-prey on Gram negative bacteria like E. coli -bore a hole in the cell wall of their prey -are highly motile Gram-negative curved rods
_______ gain energy via the oxidation of reduced inorganic chemicals, using O2 as a terminal electron acceptor.
Aerobic chemolithotrophs
Characterized members of the domain ______ typically thrive in extreme environments, such as high heat, acidity, alkalinity, and salinity.
Archaea
True or false: Scientists now understand the true diversity of microbial life and have determined the relationships between the millions of prokaryotes that exist.
FALSE
Which of the following statements about microbial diversity is true?
We are only now beginning to understand the diversity of prokaryotes.
Unlike in other anoxygenic phototrophs, in purple bacteria, the components of the photosynthetic apparatus are all located in the cell's ____ membrane.
cytoplasmic
The purple bacteria are Gram-negative organisms that can appear ______ due to their light-harvesting pigments.
-purple -orange -red