Chapter 6 Flashcards
Any substance that must be provided to an
organism.
Essential Nutrient
Nutrients required in large quantities that play
principal rules in cell structure and metabolism.
Macro-nutrients
Nutrients present in much smaller amounts that are
involved in enzyme function and maintenance of
protein structure.
Micro-nutrients
An organism that must obtain its carbon in organic
form.
Heterotroph
An organism that uses inorganic CO2 as its carbon
source.
Autotroph
Obtain energy by undergoing photosynthesis
Phototroph
Gains energy from chemical compounds
Chemotroph
Molecular movement in which atoms or molecules
move in a gradient from an area of higher density
or concentration to an area of lower concentration.
Diffusion
A case of diffusion in which water molecules move
across a selectively permeable membrane.
Osmosis
Higher concentration of dissolved material than the
interior of the cell
Hypertonic environment
Lower concentration of dissolved material than the
interior of the cell
Hypotonic solution
Has the same concentration of dissolved material
as the interior of the cell
Isotonic solution
Diffusion down a concentration gradient and
across a membrane with the assistance of special
pores or carrier molecules.
Facilitated diffusion
Moves molecules and ions against concentration
gradients from regions of lower concentration to
ones of higher concentration.
Active transport
The lowest temperature that permits a microbe
continued growth and metabolism; below this
temperature its activities are inhibited.
Minimum temperature
The highest temperature at which growth and
metabolism and proceed.
Maximum temperature
This temperature Promotes the fastest rate of growth and metabolism.
Optimum temperature
Group of microorganisms that have a optimum temperature range below 15C
Psychrophiles
Group of microorganisms that have a optimum temperature range between 20-40C.
Mesophiles
These microorganisms grow optimally at temperatures greater then 45C.
Thermophiles
The microorganisms grow between 80C to 121C
Extreme thermophiles
Organisms that require oxygen for survival
Aerobes
Organisms that are not dependent on oxygen for survival
Anaerobes
This group of organisms will use oxygen if it is available but can function without it
Facultative anaerobes
This group of organisms require a small amount of oxygen for survival
Microaerophiles
The superoxide ion is first converted to hydrogen
peroxide and normal oxygen by the action of an
enzyme called
Superoxide dismutase.
Hydrogen peroxide is also toxic to cells so it must
be degraded by an enzyme called _______ into
water and oxygen.
Catalase
Acid loving organisms (pH 0.1-5.4)
Acidophiles
These organisms prefer a neutral environment pH 5.4-8.0.
Neutrophiles
Base loving organisms, exist from pH 7.0-11.5
Alkaliphiles
Microorganisms that live optimally under high salt
concentrations
Halophiles
*Commonly bacteria in the genus Staphylococcus
A situation in which two organisms live together in
a close partnership.
Symbioses
When organisms live in a obligatory but mutually
beneficial relationship.
Mutualism
One member receives benefits, while its partner is
neither harmed nor benefited.
Commensalism
A relationship in which the host organism provides
the parasitic microbe with nutrients and a habitat.
Multiplication of the parasite usually harms the
host.
Parasitism
Bacterial cells divide using a process known as
Binary Fission
The amount of time it takes for a bacterial population to
double
Generation time
In this phase of the bacterial growth curve the
organisms do not increase significantly in number,
but they are metabolically active and therefore are producing large amounts of ATP
Lag phase
During this phase of the bacterial growth curve the
organisms divide at their most rapid rate
Log Phase
When cell division decreases to the point that new
cells are produced at the same rate as old cells die,
the number of live cells stays constant
Stationary Phase
In this stage of the bacterial growth curve the
number of cells dramatically decreases due to
unfavorable conditions within the medium
Decline (death) Phase
A mass of dividing bacterial cells that originates from a
single cell.
Colony
The observation that a liquid broth is cloudy is
termed
Turbidity
