Microbiology Chapter 7
the cell ____ is specialized to transport substances into and out of the cell
membrane
which condition is NOT optimal for survival of an anaerobic pathogen within a human host?
10% salt
what are the reasons for limited growth during the lag phase?
a period of adjustment is required numbers are often too low for accurate counting cells have not yet reached their max division rate
_____ transport requires ATP, whereas _____ transport doesn't require cell energy expenditure
active; passive
what word is used to describe organisms which can use oxygen in their cellular respiration pathways?
aerobic
an organism that prefers a pH of above 7 is referred to as a ____
alkalinophile
a ____ is any microorganism that grows best in the absence of oxygen
anaerobe
a type of antagonism where an organism produces an inhibitory compound to compete for space and nutrients is called _____
antibiosis
bacteria reproduce by ____ fission
binary
the element ___ is rep by the letter C in CHONPS
carbon
the range of temperatures for microbial growth is expressed as 3 _____ temperatures
cardinal
the diffusion of materials into a cell is largely controlled by which structure?
cell membrane
a ___-troph derives both energy and carbon from organic compounds
chemoheterotroph
what common term describes the single bacterium that gives rise to a colony?
colony forming unit
even though chemical elements are required for cellular growth, most are obtained thru chem _____ and must be broken down for use
compounds
the movement of molecules along a concentration gradient by spontaneous random motion to achieve a uniform distribution is termed ___
diffusion
any element or molecule that must be provided to an organism is called a _____ nutrient
essential
the passive movement of molecules across a membrane thru a carrier protein or protein channel is known as _____
facilitated diffusion
true or false: all cells can synthesize the 20 essential amino acids
false
true or false: microbes exist everywhere in the human body
false
the normal resident bacteria that normally inhabit the skin, GI tract, and other body sites are also referred to as normal resident ____
flora
microorganisms that are human pathogens are best described as which of the following nutritional types?
heterotrophic
in addition to carbs, proteins, and nucleic acids, microbes can utilize _____ as a source of essential nutrients
lipids
natural organic nutrients are usually the product of ?
living organisms
which bacterial phase of growth is it when the cells double every generation and far more cells are dividing than dying?
log
______ are chem substances required in large quantities by cells, such as carbon or phosphate
macronutrients
inorganic compunds
minerals, carbon dioxide, water
describe the features of active transport
movement is usually against the diffusion gradient involves membrane proteins requires ATP expenditure
the element _____ is represented by the letter N in CHONPS
nitrogen
macro nutrients in cells include carbohydrates, proteins, lipids, and _____ acids
nucleic
the best term for any chemical substance that must be provided to a cell for normal metabolism and growth
nutrient
what term is used to describe the "best" temp to support a microbe's growth?
optimal temperature
the majority of carbon compounds that a cell requires are:
organic
organisms that have the ability to adapt to wide variations in solute concentration are referred to as
osmotolerant
organisms that derive nutrients from the living hosts are called ____
parasites
_____ is a relationship b/w 2 organisms where the host is harmed and the colonizer benefits
parasitism
the engulfment of large particles or cells into vesicles within a cell is specifically called
phagocytosis
the element ____ is rep by the letter P in CHONPS
phosphorus
a ____-troph is an organism that uses the sun's light to provide the chemical energy to produce sugar for cellular respiration
photo
prior to refrigeration, salting was used to prevent microbial growth in foods by causing ____ in bacterial cells
plasmolysis
examples of organic nutrients
proteins; nucleic acids; methane; carbs
organisms that can grow slowly in cold, but have optimum temperatures above 20C are called
psychrotrophs
a ______ is a critical number of cells required to release inducer molecules in order to form a biofilm
quorum
what is NOT an important role for water in the growth and metabolism of cells
resistance of osmotic pressure
which element is rep by S in CHONPS?
sulfur
_____ is a close nutritional association b/w individuals from 2 species that may be helpful, harmful or neither to both members
symbiosis
the speed and continuous movement of atoms and molecules is largely controlled by
temperature
autotrophs are special because
they can use fairly free energy sources to make sugar
true or false: each different carrier protein can only bind and transport a certain molecule.
true
what term is used to describe the cloudiness of a broth culture?
turbidity