Ch. 7: Microbial nutrition, ecology, & growth Flashcards
(74 cards)
The term chemotroph refers to an organism that
gets energy by oxidizing inorganic & organic chemical compounds.
Organisms that feed on dead organisms for nutrients are called
saprobes.
Aerobic respiration is an example of
chemoheterotrophy.
The methanogens, producers of methane gas, require environments that
are anaerobic with hydrogen gas and CO2.
The use of energy by a cell to enclose a substance in its membrane by forming a vacuole and engulfing it is called
endocytosis.
The movement of molecules from an area of high concentration to an area of lower concentration is called
diffusion.
Facilitated diffusion and active transport require __________________ to mediate the movement across the plasma membrane.
a carrier protein
The movement of substances from lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and cell expenditure of energy is called
active transport.
What kind of microorganisms would find hypotonic conditions very detrimental?
protozoa
In ________ conditions, the cell wall will help prevent the cell from bursting.
hypotonic
A cell with 1% salt inside lives in the ocean, which is 3% salt. This is what kind of environment?
Hypertonic
An organism with a temperature growth range of 50°C to 70°C would be called
thermophile
Cultures of a bacterial species were incubated at various temperatures. After incubation, there was no growth at 37°C and 70°C, but abundant growth in the refrigerator. What term could be used for this species?
Psychrophile
A microorganism that does not have catalase or superoxide dismutase would find it difficult to live in an environment with
oxygen.
Which two enzymes, and in what order, catalyze the steps converting the toxic superoxide ion to less harmful oxygen gas?
superoxide dismutase and catalase
The E. coli that normally live in the human large intestines and produce vitamin K that the body uses would be best termed a ________ relationship.
mutualistic
When microbes in close nutritional relationship and one benefits but the other is not harmed, it is called
commensalism.
The phase of the bacterial growth curve in which newly inoculated cells are adjusting to their new environment, metabolizing but not growing is the
lag phase.
The phase of the bacterial growth curve that shows the maximum rate of cell division is the
log phase.
viable cell count only measures:
living things
Which tool is so expensive that it is not used at most hospitals in the world?
flow cytometer
autotroph
a microorganism that requires only inorganic nutrients and whose sole source of carbon is carbon dioxide.
active transport
nutrient transport method that requires carrier proteins in the membranes of the living cells and the expenditure of energy
chemoautotrophs
an organism that relies upon inorganic chemicals for its energy and carbon dioxide for its carbon; AKA chemolithotroph
