Deck 6: Microbial Nutrition

Question 1

Organisms that use reduced, preformed organic molecules as carbon sources are

A) auxotrophs.
B) autotrophs.
C) prototrophs.
D) heterotrophs.

Answer 1

D

Question 2

Organisms that obtain energy from light are called

A) chemotrophs.
B) lithotrophs.
C) organotrophs.
D) phototrophs.

Answer 2

D

Question 3

The trace amounts of micronutrients needed by microorganisms are usually supplied as inadvertent contaminants in water and regular media components.

Answer 3

True

Question 4

Copper (Cu) is considered a micronutrient.

Question 5

Sulfur can be obtained from inorganic sources only.

Question 6

Which of the following is not considered a macronutrient?

A) carbon (C)
B) calcium (Ca)
C) potassium (K)
D) cobalt (Co)

Question 7

Organisms that obtain electrons from the oxidation of inorganic compounds are called

A) chemotrophs.
B) lithotrophs.
C) organotrophs.
D) phototrophs.

Question 8

Which of the following best describe a possible energy source for a chemoorganotroph.

A) glucose
B) carbon dioxide
C) oxidized metals
D) light
E) none of the choices

Question 9

Organisms that can use carbon dioxide as their sole or principal source of carbon are

A) auxotrophs.
B) autotrophs.
C) prototrophs.
D) heterotrophs.

Question 10

Organisms that obtain electrons from the oxidation of organic compounds are called

A) chemotrophs.
B) lithotrophs.
C) organotrophs.
D) phototrophs.

Question 11

Bacteria that can utilize methane, methanol, carbon monoxide, formic acid, and a few related one-carbon molecules as their principal source of carbon are called ____________.

A) methylotrophic
B) carbotrophic
C) monotrophic
D) autotrophic

Question 12

Nitrogen can be obtained from either organic or inorganic sources.

Question 13

Although a particular microbial species usually can be defined as a particular nutritional type, some show great metabolic flexibility and alter their metabolic patterns in response to environmental changes.

Question 14

Phosphorus can be obtained from organic sources only.

Question 15

Microbial degradation of a relatively indigestible compound promoted by the presence of readily utilized nutrient is called

A) mixotrophy.
B) promotion.
C) cometabolism.
D) enhancement.

Question 16

Elements that are required in relatively large amounts by microorganisms are called

A) multivitamins.
B) meganutrients.
C) macronutrients.
D) macromolecules.

Question 17

Zinc (Zn) is considered a macronutrient.

Question 18

Which of the following features is most likely to be associated with a lithotroph?

A) contains chlorophyll
B) oxidization of an inorganic substrate
C) ferments carbohydrates
D) parasitism of humans

Question 19

Organisms that obtain energy from the oxidation of either organic or inorganic compounds are called

A) chemotrophs.
B) lithotrophs.
C) organotrophs.
D) phototrophs.

Question 20

Which of the following is not considered a micronutrient?

A) manganese (Mn)
B) magnesium (Mg)
C) zinc (Zn)
D) copper (Cu)

Question 21

Nutrients can be concentrated from dilute solutions by

A) pinocytosis.
B) endocytosis.
C) active transport and group translocation.
D) electron transport.

Question 22

The movement of molecules across a membrane from an area of higher concentration to an area of lower concentration with the use of a carrier molecule embedded in the membrane is called

A) facilitated diffusion.
B) osmosis.
C) passive diffusion.
D) active transport.

Question 23

Permease proteins that aid in the transport of nutrients resemble enzymes in their specificity for the substance to be transported. Each carrier is selective and will transport only a closely related set of substances.

Question 24

A wide variety of microorganisms are commercially used to manufacture _________ for human consumption.

A) vitamins
B) sugars
C) fatty acids
D) none of the choices

Question 25

__________ are carrier proteins embedded in the membrane that increase the rate of diffusion of specific molecules across selectively permeable membranes.

Question 26

__________ membranes allow some molecules to pass but not others.

A) Permeable
B) Inverted monolayer
C) Selectively permeable
D) Impermeable

Question 27

Many bacteria facilitate the uptake of iron by secreting low molecular weight molecules, called ___________, to form complexes with the iron that can then be readily transported into the cell.

Question 28

__________ __________ are required organic compounds because they are essential cell components or precursors of such components that cannot be synthesized by the organism.

Question 29

The extreme insolubility of ferric iron leaves little free iron available for transport into bacterial cells.

Question 30

The movement of molecules across a membrane from an area of lower concentration to an area of higher concentration with the expenditure of energy is called

A) facilitated diffusion.
B) osmosis.
C) passive diffusion.
D) active transport.

Question 31

The movement of molecules from an area of higher concentration to an area of lower concentration without the participation of specific carrier molecules is called

A) facilitated diffusion.
B) osmosis.
C) passive diffusion.
D) active transport.

Question 32

Which of the following processes can be used to bring nutrients into a cell against a concentration gradient?

A) active transport
B) facilitated diffusion
C) passive diffusion
D) active transport and facilitated diffusion

Question 33

Different transport systems for the same nutrient that are part of the same organism are usually regulated in different ways.

Question 34

Which of the following is not a major class of growth factors?

A) amino acids
B) purines and pyrimidines
C) vitamins
D) nucleic acids

Question 35

Transport of two different substances can be linked. If the transport is in the same direction it is called __________; if the transport is in opposite directions it is called __________.

Question 36

Media containing some ingredients of unknown chemical composition are called __________ media.

A) undefined
B) complex
C) defined
D) synthetic

Question 37

Small organic molecules called __________ function as enzyme cofactors.

Question 38

Organisms usually have only a single transport system for any nutrient.

Question 39

Agar is an excellent solidifying agent for microbiological media because

A) it is not degraded by most microorganisms.
B) solid agar remains solid until the temperature is raised to 90 $\degree$ C, and liquid agar remains liquid if the temperature is lowered to 45 $\degree$ C.
C) it is not degraded by most microorganisms and solid agar remains solid until the temperature is raised to 90 $\degree$ C, and liquid agar remains liquid if the temperature is lowered to 45 $\degree$ C are correct.
D) agar provides an excellent source of nutrition for a variety of different microorganisms.

Question 40

Which of the following is a characteristic of active transport?

A) saturable uptake rate
B) use of ATP or a proton gradient as a source of metabolic energy
C) can move materials against a concentration gradient
D) all of the choices

Question 41

Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes). Among the halophiles, mannitol fermenters release acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol fermenter, a nonhalophilic mannitol fermenter, and a halophilic mannitol nonfermenter. Thus, the medium is acting as a __________ medium.

A) selective
B) differential
C) selective and differential
D) neither selective nor differential

Question 42

All fastidious microorganisms require which of the following for growth?

A) oxygen
B) temperatures near normal for the human body
C) extra nutrients (such as whole blood)
D) iron

Question 43

The size and shape of a colony is not useful for identification of a microorganism because most microorganisms produce colonies that are indistinguishable from one another.

Question 44

For surface cultivation of microorganisms, a sulfated polymer called agar can be extracted from __________ and added to liquid media in order to cause it to solidify.

A) bacteria
B) animal fat
C) algae
D) fungi

Question 45

A growth medium that distinguishes among different groups of bacteria on the basis of their biological characteristics is called a __________ medium.

A) selective
B) differential
C) enrichment
D) transport

Question 46

A growth medium that favors the growth of some microorganisms but inhibits the growth of other microorganisms is a __________ medium.

A) selective
B) differential
C) selective and differential
D) neither selective nor differential

Question 47

Which of the following can be used to isolate pure cultures of bacteria from mixtures?

A) spread plates
B) streak plates
C) pour plates
D) all of the choices

Question 48

Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes); nonhalophiles will not grow. Among the halophiles, mannitol fermenters will produce acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol fermenter and a halophilic mannitol nonfermenter. In this case, the medium is acting as (a) __________ medium(s).

A) selective
B) differential
C) selective and differential
D) enrichment

Question 49

Macroscopically visible growths or clusters of microorganisms on solid media are called __________.

Question 50

Media in which all components and their concentration are known are called __________ media.

A) transport
B) defined
C) selective
D) enrichment

Question 51

A given medium can be either selective or differential but not both.

Question 52

Serial dilutions can be used to estimate the total number of bacterial cells in a solution, including living and dead cells.

Question 53

Colonies grow most rapidly at the __________ where oxygen and nutrients are readily available; however, they grow less rapidly at the __________ where these materials have been depleted.

Question 54

Mannitol salt agar (MSA) only allows the growth of halophiles (salt-loving microbes). Among the halophiles, mannitol fermenters release acid that turns the pH indicator yellow; mannitol nonfermenters leave the medium red. Onto MSA you inoculate a halophilic mannitol nonfermenter and a nonhalophilic mannitol nonfermenter. Here the medium acts as a __________ medium.

A) selective
B) differential
C) selective and differential
D) enrichment

Question 55

You would like to culture a bacterium that is growing in the lung of a human patient with pneumonia. Which media would be of most use in culturing this organism?

A) transport media
B) mannitol salt agar
C) MacConkey's agar
D) complex medium supplemented with whole blood
E) none of the choices

Question 56

Growth media that will support the growth of many different types of microorganisms are called __________ __________ growth media, whereas those that are supplemented by blood or other rich nutrient sources in order to support the growth of fastidious organisms are called __________ media.

Question 57

Blood agar is both a differential and enriched medium.