Ch 6: Microbial Nutrition and Growth

Most microbes prefer environments near or at a pH of ______. a. 4 b. 7 c. 9

7

How much water does a cell contain?

70%

What word is used to describe organisms which can use oxygen in their cellular respiration pathways? a. Oxygenators b. Oxygenobic c. Anaerobic d. Aerobic

Aerobic

What is a microaerophile?

An aerobic bacterium that requires oxygen at a concentration less than that in the atmosphere

True or false: A colony forming unit is a single cell.

False It cannot be true because while a single cell can form a colony, in many cases, a colony forms from multiple cells or clusters of cells.

Which term describes the length of time of a microbial species needs to divide? a. Generation time b. Growth time c. Mitosis time d. Binary fission

Generation time

What term is used to describe a graphical representation of a change in population size over time? a. Lag phase b. Histogram c. Growth curve

Growth curve

Having a lower osmotic pressure than a reference solution is known as what? a. isotonic b. hypotonic c. hypertonic

Hypotonic

Which of the following types of radiation can damage microbes? a. Ionizing b. Neutron c. Alpha d. Ultraviolet

Ionizing and ultraviolet

Which of the following would describe a solution which is well balanced for a cell? a. Isotonic b. Hypertonic c. Hypotonic

Isotonic

Can obligate aerobe grow without oxygen? Yes/No

No. Obligate aerobe needs oxygen to grow.

______ is the acquisition of chemical substances by organisms for use as an energy source or as building blocks of cellular structures. a. Nutrition b. Metabolism

Nutrition

Which term is used exclusively to describe water's movement across a selectively permeable membrane? a. Osmosis b. Diffusion c. Hypotonic d. Active transport

Osmosis

Why is refrigeration of leftover food an effective way to prevent spoilage? a. Refrigeration denatures most toxins that may have been produced by food-associated microbes. b. Refrigeration destroys most microbes that lead to food spoilage and food-borne illness. c. Refrigeration temperatures are not optimal for reproduction and growth of food-associated pathogens.

Refrigeration temperatures are not optimal for reproduction and growth of food-associated pathogens.

Which term describes any close relationship between two organisms? a. Parasitism b. Mutualism c. Symbiosis d. Commensalism

Symbiosis

True or False. Microaerophiles are harmed by normal atmospheric concentrations of oxygen but require a small amount of it in metabolism.

True

True or false: Different microbes grow in a wide variety of environmental conditions; however, most have preferences for certain temperatures, pH, and atmospheric gases.

True

True or false: Minerals needed for some enzymes to function are useful at low concentrations, but the same minerals can be toxic in high concentrations.

True

True or false: Nutrition is the acquisition of chemical substances by organisms for use as an energy source or as building blocks of cellular structures.

True

True or false: Oxygen can be toxic for some microbes.

True

True or False. Facultative anaerobes do not require oxygen for metabolism but use it when it is present.

True.

Can an aerobe use oxygen? Yes/No

Yes

What compound is the most abundant in a cell? a. H2O b. CH4 c. Glucose d. CO2 e. NH3

a. H2O

What name is given to relationships between organisms where one organism benefits at the expense to another organism? a. Parasitism b. Mutualism c. Commensalism

a. Parasitism

Nutrient transport method that requires carrier proteins in the membranes of the living cells and the expenditure of energy. a. active transport b. simple diffusion c. facilitated diffusion

a. active transport

An organism that does not use oxygen in its metabolic pathways but can survive in its presence is a(n) _______. a. aerotolerant anaerobe b. facultative anaerobe c. microaerophile d. obligate aerobe e. obligate anaerobe

a. aerotolerant anaerobe

Which of the following environmental factors are likely to have the greatest influence on microbial growth? a. Gases such as carbon dioxide and oxygen b. pH c. Gases such as helium and argon d. Pressures e. Rock formations f. Temperature

a. gases such as carbon dioxide and oxygen b. pH d. pressures f. temperature

Having a greater osmotic pressure than a reference solution is known as what? a. hypertonic b. isotonic c. hypotonic

a. hypertonic

How is iron important in microbial metabolism? a. important component of the cytochrome proteins of cell respiration. b. regulatory element for eukaryotic genetics. c. important for cell transport d. protein synthesis and membrane function

a. important component of the cytochrome proteins of cell respiration.

Based on their ability to use oxygen and deal with its toxic properties, identify the categories found among microbes. a. neither use oxygen nor detoxify it b. can use oxygen but cannot detoxify it c. can use oxygen and detoxify it d. do not use oxygen but can detoxify it

a. neither use oxygen nor detoxify it c. can use oxygen and detoxify it d. do not use oxygen but can detoxify it

What is potassium essential for in microbial metabolism? a. protein synthesis and membrane function b. cell transport c. stabilizer of the cell wall and endospores of bacteria. d. component of chlorophyll and stabilizer of membranes and ribosomes.

a. protein synthesis and membrane function

A general term used to denote a situation in which two organisms live together in a close partnership is known as? a. symbiosis b. mutualism c. commensalism d. parasitism

a. symbiosis

A microbe that can use gaseous oxygen in its metabolism and possesses the enzymes needed to process toxic oxygen products is called a(n) _______.

aerobe

Microbes that lack the metabolic enzyme systems for using oxygen in respiration are called ______. a. microaerophiles b. aerobes c. anaerobes

anaerobes

What word is used to describe organisms which do NOT use oxygen in their cellular respiration pathways? a. Anaerobic b. Aerobic c. Passive aerobes d. Oxygen neutral

anaerobic

How is sodium important for microbial metabolism? a. protein synthesis and membrane function b. cell transport c. stabilizer of the cell wall and endospores of bacteria. d. component of chlorophyll and stabilizer of membranes and ribosomes.

b. cell transport

An organism that respires using oxygen when it is present but can switch to an alternative anaerobic pathways when it is absent is a(n) _______. a. obligate aerobe b. facultative anaerobe c. microaerophile d. obligate anaerobe e. aerotolerant anaerobe

b. facultative anaerobe

Bacteria must replicate their DNA and synthesize new cell components prior to ______. a. binary fission b. mutation c. sexual reproduction d. transcription

binary fission

Prior to ______, a bacterial cell enlarges by synthesizing new cell components and duplicates its chromosome. a. binary fission b. transcription c. mitosis d. sexual reproduction

binary fission

The majority of bacteria grow by a process called ______. a. budding b. binary fission c. hyphal formation d. mitosis

binary fission

What are "zinc fingers"?

binding factor that helps enzymes adhere to specific sites on DNA

Which is FALSE regarding binary fission? a. It is a type of asexual reproduction. b. Division involves the formation of a protein band that resembles actin and tubulin of eukaryotes. c. Like meiosis in eukaryotes, it specifically produces daughter cells with genetic variation. d. Daughter cells are identical to each other.

c. Like meiosis in eukaryotes, it specifically produces daughter cells with genetic variation.

The movement of molecules from an area of high concentration to an area of lower concentration is called _______. a. active transport b. facilitated diffusion c. diffusion d. endocytosis e. osmosis

c. diffusion

The phase of the bacterial growth curve in which newly inoculated cells are adjusting to their new environment, metabolizing but not growing, is the _______. a. prophase b. log phase c. lag phase d. death phase e. stationary phase

c. lag phase

Simple diffusion is best described as the movement of atoms or molecules from an area ______ to an area ______. a. of lower concentration; of higher concentration b. where they are far apart; where they are closer together c. of higher concentration; of lower concentration d. where they are uniformly distributed; where they are closer together

c. of higher concentration; of lower concentration

The engulfment of large particles into vesicles within a cell is called ______. a. pinocytosis b. endocytosis c. phagocytosis d. exocytosis

c. phagocytosis

How is calcium important in microbial metabolism? a. protein synthesis and membrane function b. cell transport c. stabilizer of the cell wall and endospores of bacteria. d. component of chlorophyll and stabilizer of membranes and ribosomes.

c. stabilizer of the cell wall and endospores of bacteria.

________ is an important mineral for the stabilization of cell walls and endospores, whereas ________ is needed for cell transport.

calcium; sodium

Bacterial cells are enumerated as "colony-forming units" because .... a. chains or clusters of bacterial cells may form a colony b. motility of cells on plates confuses a direct cell count c. you can only count colonies, not individual cells d. the number of cells in a colony can vary with the incubation time

chains or clusters of bacterial cells may form a colony

From which body site could a facultative anaerobic bacterial pathogen be isolated? a. deep wound b. surface of skin c. intestine d. any of these

d. any of these

Facilitated diffusion is limited by ________. a. the size of the cell b. substrate concentration c. size of the pores in the membrane d. carrier proteins in the membranes e. osmotic pressure

d. carrier proteins in the membrane

Aerobic respiration is an example of _______. a. photoautotrophy b. methanoheterophy c. photoheterotrophy d. chemoheterotrophy e. photosynthesis

d. chemoheterotrophy

How is magnesium important in microbial metabolism? a. protein synthesis and membrane function b. cell transport c. stabilizer of the cell wall and endospores of bacteria. d. component of chlorophyll and stabilizer of membranes and ribosomes.

d. component of chlorophyll and stabilizer of membranes and ribosomes.

How is zinc important in microbial metabolism? a. protein synthesis and membrane function b. cell transport c. stabilizer of the cell wall and endospores of bacteria. d. regulatory element for eukaryotic genetics.

d. regulatory element for eukaryotic genetics.

The term facultative refers to ________. a. using light for energy production b. using oxygen for metabolism c. existing in a very narrow niche d. the ability to exist in a wide range of conditions e. using chemicals for energy production

d. the ability to exist in a wide range of conditions

The E. coli that normally live in the human large intestines and produce vitamin K for the body to use would best be termed a _______ relationship. a. saprobic b. commensal c. parasitic d. none e. mutualistic

e. mutualistic

A microaerophile ________. a. grows with or without oxygen b. grows best in an anaerobic jar c. needs normal atmospheric levels of oxygen d. none e. requires a small amount of oxygen but won't grow at normal atmospheric levels

e. requires a small amount of oxygen but won't grow at normal atmospheric levels

A nutrient that must be provided to an organism because it cannot be manufactured metabolically is called a(n) _______ nutrient.

essential

Any substance that must be provided to an organism to satisfy a nutritional need is termed a(n) ________ nutrient.

essential

Antimicrobial agents such as heat and disinfectants rapidly accelerate the death phase in all populations, but microbes in the ____________ growth phase are more vulnerable to these agents than those that have entered the stationary phase.

exponential

Which of the following describes an organism that does not require oxygen but can use it when it is present? a. Obligate aerobe b. Facultative anaerobe c. Microaerophile d. Obligate anaerobe

facultative anaerobe

Which of the following describes an organism that does not require oxygen but can use it when it is present? a. Obligate aerobe b. Obligate anaerobe c. Facultative anaerobe d. Microaerophile

facultative anaerobe

In binary fission, the doubling time of a particular microbial species is also known as its _________ time.

generation

A graphical representation of the change in population size over time is called a(n) _______ curve.

growth

The term used to describe the condition where the solute concentration within the cell is equal to the solute concentration in the surrounding environment is _______.

isotonic

The term used to describe the condition where the solute concentration within the cell is equal to the solute concentration in the surrounding environment is _________.

isotonic

Under ______ conditions, the environment is equal in solute concentration to the cell's internal environment. a. hypotonic b. isotonic c. hypertonic

isotonic

What are microorganisms that grow at intermediate temperatures?

mesophile

The majority of medically significant microorganisms are ______, since their temperature range includes human body temperature. a. thermophiles b. psychrophiles c. mesophiles

mesophiles

The largest group of medically important microorganisms are _________ bacteria that have an optimal growth temperature in the range of human body temperature.

mesophilic, mesophile, or mesophiles

A microbe that is harmed by normal atmospheric concentrations of oxygen but requires a small amount of oxygen in its metabolism is a(n) ______. a. obligate anaerobe b. microaerophile c. anaerobe d. facultative anaerobe

microaerophile

An aerobic bacterium that requires oxygen at a concentration less than that in the atmosphere is called a(n) ___________.

microaerophile.

A(n) ______ is a microbe which prefers environments near or at a pH of 7. a. neutrophile b. alkalinophile c. acidophile

neutrophile

All organisms require an influx of substances from their habitat to meet their _______ needs for chemical elements and energy.

nutritional

A strictly aerobic organism, requiring oxygen for survival, is referred to as a(n) _______ aerobe.

obligate

What word describes a microbe that must have oxygen to survive? a. Passive aerobe b. Facultative aerobe c. Obligate aerobe d. Semi aerobe

obligate aerobe

What term is used to describe the "best" temperature to support a microbe's growth? a. Maximum temperature b. Optimal temperature c. Steady state temperature

optimal temperature

A microbe's ______ temperature covers a small range that promotes the fastest rate of growth and metabolism. a. optimum b. maximum c. minimum

optimum

The temperature at which a species shows the most rapid growth rate is known as the cell's _________ temperature.

optimum, or optimal

The diffusion of water across a selectively permeable membrane in the direction of lower water concentration is called _______.

osmosis

The diffusion of water across a selectively permeable membrane in the direction of lower water concentration is called __________.

osmosis

Prior to refrigeration, how did salting help preserve foods? a. bacteriophages killed the bacteria in foods b. UV light killed the bacteria in foods c. osmotic pressure prevented growth of microbes

osmotic pressure prevented growth of microbes

An organism that benefits at the expense of another is called a _____.

parasite

Which type of organism causes harm to the body of the living host in which or on which it lives? a. autotroph b. parasite c. commensal d. saprobe

parasite

The cell actively engulfs large particles into vesicles during the endocytic process of __________.

phagocytosis

The type of endocytosis that involves formation of vacuoles following engulfment of whole cells or large particles is called ______. a. phagocytosis b. exocytosis c. pinocytosis

phagocytosis

After water, the most common type of compound found in cells is _______. a. sugar b. protein c. salt d. fat

protein

Which type of macromolecules are the most abundant in cells? a. proteins b. carbohydrates c. nucleic acids d. lipids

proteins

Ultraviolet light and ionizing rays are types of ________ that can damage microbes.

radiation

Prior to refrigeration, salting was used to prevent microbial growth in foods by causing bacterial cells to ______. a. shrivel b. burst c. fragment

shrivel

Which of the following is the movement of small, nonpolar molecules along a concentration gradient by spontaneous random motion to achieve a uniform distribution? a. Group translocation b. Simple diffusion c. Active transport d. Facilitated diffusion

simple diffusion

A close partnership between individuals from two species that may be helpful, harmful, or neither to either member is called _______.

symbiosis, or symbiotic.

Cell cytoplasm is mostly made up of ________.

water