microbio exam 2: previous questions

viruses

simply want to replicate

viruses are not considered living because

they have no ribosomes

capsomeres

are the protein unites that make up the capsid

budding, when it refers to viruses, has to do with

replication of enveloped viruses

clostridium botulinum produces a toxin because

it contains a prophage

the best way to prevent a viral infection is

get vaccinated if a vaccine is available

if you have a pet potato and you dont want it to get sick, keep it away from

viroids

if you see a deer staggering around the woods, you might want to avoid it because it may have

chronic wasting disease

prions

are altered brain proteins

the breakdown of lactose into glucose and galactose

is a spontaneous reaction

ATP is the energy currency of living cells because

the amount of energy that it takes to make ATP reasonable for the cell

enzymes

are always proteins, catalyze only spontaneous reactions, and catalyze reactions that might take a year to occur on their own

enzyme activity

slows down at temperatures below and greater than optimal temperature

wild type e coli does not require as a nutrient

essential metabolites

with respect to temperature, organisms that grown optimally at human body temperature of 37 degrees celsius are referred to as

mesophiles

which statement is correct

humans, dogs, and cats produce superoxide and superoxide dismutase

in which phase(s) of growth are bacterial cells growing most rapidly

log phase only

a microorganism that is found in an alkaline (pH 10.0) environment

will probably die in the neutral pH medium

which of these methods might count dead cells found in an original bacterial culture

direct microscopic count

proteins are not considered nutrients for a cell because

they are simply too big to get into the cell

nitrogen fixation

occurs in some microorganisms

which statement is correct

e coli is a chemoheterotroph while most of the archaea are chemoautotrophs

the type of ATP generation where a phosphate is donated directly from an organic molecule is

substrate level phosphorylation

one purpose of fermentation is

to reduce pyruvic acid

the oxidation of glucose ultimately to carbon dioxide is an example of

catabolism

oxidation phosphorylation is direclty associated with

the electron transport chain

in biological oxidations, what is typically removed from a molecule

hydrogen atoms

streptococcus typically carries out fermentation only because

it is missing an enzyme in the krebs cycle

NAD+ is

a coenzyme

most of the CO2 released by an organism performing repiration is released in

the krebs cycle

a major difference between fermentation and respiration is

fermentation uses an organic final electron acceptor

we need molecular oxygen

to serve as a final electron acceptor only

ATP synthase is invovled in

oxidative phosphorylation

the proton motive force

transports certain amino acids into the cell

the core pathways

are glycolysis and the krebs cycle

the poison, cyanide, interferes directly with

the electron transport chain

e coli, in the presence of molecular oxygen and nitrate, predominantly carries out

aerobic respiration

which of the following contains the most energy

NADH

fatty acids, which are break down products from fats, enter metabolism

in one of the core pathways

what is the fate of pyruvic acid in an organism that uses anaerobic respiration

most of its carbon are oxidized in the krebs cycle

which of the following statements are true

viruses are not cellular, so they are not considered to be alive

which is not associated with a viral capsid

protects nucleic acid, receptor binding sites, shape of the virus, is composed of capsomeres

viral envelopes

are derived from the cell membrane of the host cell

when an animal DNA virus infects a cell

DNA replication takes place inside of the host cell

one thing that a bacteriophage normally does than an animal virus may or may not do is

lyse a host cell

lysogeny

sometimes results in the host cell producing toxins

if you were setting up an experiment on viruses, which of the following would be important to maintain the viruses used in the experiment

host cells

an oncogenic virus

is a cancer causing animal virus

another name for mad cow disease is

bovine spongiform encephalopathy

the model of how a prion works is that

the infectious protein causes normal brain proteins to become altered

enzymes

only catalyze spontaneous reactions

the factor that affects enzyme activity that would most likely denature the enzyme is

enzyme concentration

B vitamin is an example of

a coenzyme and a cofactor

which of the following is not considered a nutrient for a microorganism

protein

which of the following statments is true

molecular oxygen is an electron acceptor in some living organisms

the optimal growth temperature of a bacterium is most closely related to teh optimal temperatjre of

functioning of enzymes

organisms that cannot produce superoxide dismutase are

anaerobic

the process whereby some microorganisms converts atmospheric nitrogen into biologically utilizable compounds is called

nitrogen fixation

a microbiology student noticed that a culture broth tube was turbid at the surface but clear throughout the rest of the tube. what can this student correctly conclude

the organisms are aerobes

a disadvantage to the dilution and plating technique is

it may not count aerobes burried in the agar

stationary growth phase is achieved because

cells run out of nutrients and end products build up

direct transfer of a phosphate group from an organic molecule to ADP is called

substrate level phosphorylation

when lactic acid is converted into pyruvic acid, NADH is formed. the reaction that forms NADH is an

reduction

microorganisms found relatively deep below the surface of the earth are most likely

chemoautotrophs

organisms that are basically saprophytes (eat dead decaying organic matter) like humans are

chemoheterotrophs

which statement is true

glucose has more energy than two pyruvic acids

what is transferred to NAD+ during the breakdown of glucose

electrons

fermentation accomplishes

getting rid of pyruvic acid

what is the fate of pyruvic acid in an organism that uses anaerobic respiration

it is ultimately oxidized in the krebs xyxle

streptococcus, which lacks an enzyme in the krebs cycle

gets its energy from glycosis, ferments lactic acid only, does not use an electron transport chain for energy production

in a test tube of medium constantly exposed to oxygen at the surface of the medium, ecoli, which can respire and ferment, form some acidic fermentation products. this occurs because

oxygen is being depleted at the bottom of the tube

which of the following is not a characteristic of fermentation

end products can include acid, gases, and alcohols. does not require oxygen. occurs following gycolysis. and utilized pyruvic acid

once pyruvic acid enters the fermentation reactions, the most important and direct produce of fermentation that benefits the fermenting cell is

NAD+

the proton motive force is

none of the aboce

phosphorylation

is the addition of phosphate to a molecule

which statement is true

electrons on NADH have more energy than electrons that are transferred to oxygen

the conversion of pyruvic acid to lactic acid is an example of

reduction

ATP synthase

is the site of oxidative phosphorylation

which statement is true

amino acids enter the core pathways at glycolysis and the krebs cycle

which of the statements is true

catabolism involved oxidation reactions and reduction reactions

the correct sequence of events in an animal virus lytic infection cycle is

attachment, penetration, uncoating, biosynthesis, maturation, and release

viruses

vary in shape and contain nucleic acid

a viral envelope is acquired during which of the following steps

release

viruses are not considered living because

they do not produce ATP or have ribosomes

a disease caused by viroids is

potato spindle tuber disease

lysogenic conversion is

when a lysogenized cell simply has a new characteristic

if you were setting up an experiment on viruses, which of the following would be important to maintain the viruses used in the experiment

host cells

bovine spongiform encephalopathy is

mad cow disease

oncogenic viruses

cause some forms of cancer

which statement is true

all enzymes only catalyze spontaneous reactions

enzyme activity is influenced by

substrate concentration, acidity, and alkaline and temperature

which of the following are nutrients for bacteria

amino acids, ammonium ion, glucose

nitrogen fixation

someday might put a dent into the world hunger problem

superoxide dismutase

is found in all animals, plants, and some bacteria

the optimal growth temperature of a bacterium is most closely related to the optimal temperature for

functioning of enzyme

a microorganism that prefers a temperature around 20 celsius but can cause serious food spoilage at refrigeration temperatures is referred to as a

psychotroph

a microbiology student noticed that a culture broth tube was very turbid at the surface but clear throughout the rest of the tube. what can this student correctly conclude

the organisms are aerobes

the quickest and most convenient method to measure bacterial growth is

turbidity measurment

one possible drawback to using the direct microscopic count is

you are counting dead and living cells

the phase of growth where cells are adjusting to the growth conditions is the

lag phase