glucose
molecules broken down in cellular respiration, providing fuel for the cell
ATP
energy rich molecule directly powers cell work
function only in a limited set of enzymes and cofactors
Trace elements are found in bacterial cells in very small amounts because they __________.
growth factors
Organic micronutrients are commonly called __________.
both organic and inorganic compounds
Based on the functional roles of phosphate in various microbial metabolisms, deduce which compounds phosphate exists as in microorganisms.
most available nitrogen is in organic forms
Which of the following statements is FALSE?
phosphorus, selenium, and sulfur
All microorganisms require
iron
Which is an example of a micronutrient?
proteins
The class of macromolecules in microorganisms that contributes MOST to biomass is
oxygen
In aerobic respiration, the final electron acceptor is
Cytochromes, flavoproteins, and NADH dehydrogenases all can be membrane-associated.
Which of the following is NOT membrane-associated?
Cells require much less P to grow than N, so extra P will be used for ATP synthesis and result in a faster growth rate.
When culturing a chemoorganoheterophic bacterium, what outcome is LEAST likely to occur if ammonia and phosphate are provided at equal concentrations?
false
A bacterial isolate that grows better on a nutrient agar plate supplemented with amino acids but still grows in a nutrient agar plate lacking amino acids suggests amino acids are trace nutrients for the isolate.
true
During the electron transport process, protons and electrons become physically separated in the cell membrane.
Both organisms would grow equally well.
In microbiology lab, you make three different culture plates: one general purpose plate, one selective media plate, and one differential media plate. Unfortunately, you forget to label the different plates, so you do not know which is which. To determine the identity of each plate, you inoculate it with two different strains of laboratory bacteria. Which of the following results would indicate the plate you used was the general purpose media?
differential media
In microbiology lab, you make three different culture plates: one general purpose plate, one selective media plate, and one differential media plate. Unfortunately, you forget to label the different plates, so you do not know which is which. To determine the identity of each plate, you inoculate it with two different strains of laboratory bacteria. After inoculation, you see that a particular plate has allowed both organisms to grow, but one has changed color. Which plate do you think this is?
enrichment media
Which of the following types of culture media would best be used by a veterinarian to grow any bacteria in a blood sample?
inhibit the growth of certain bacteria
change the color of some organisms based on their metabolic characteristics
change the color of some organisms based on their metabolic characteristics
Which of the following would you expect to be a function of MacConkey agar? Mark all that apply.
glucose
Which of the following would NOT be required to grow an autotroph?
to get as many organisms as possible to grow in the culture medium
A nurse takes a urine sample from a patient suspected of having contracted a urinary tract infection. The nurse uses careful aseptic technique in collecting the sample. Which is NOT a reason for using aseptic technique in this situation?
a series of practices to avoid contamination
Aseptic technique refers to
complex/minimal
To ensure growth of a newly discovered bacterium with unknown nutritional requirements, it would be best to begin with a ________ medium rather than a ________ medium.
given off as heat
In metabolism, energy that is not used
anabolism
The reactions involved in producing larger compounds from smaller compounds is called
catabolic reactions
Where does the energy required for anabolic reactions come from?
is an example of anabolism.
The use of amino acids to make proteins
chemoorganotroph
A defined culture medium must supply all of the nutrients an organism needs, including essential biochemicals that the cell cannot synthesize. Based on the following recipe, this defined medium could support the growth of certain members of what group? Recipe: 7 g of K2HPO4; 2 g of KH2PO4; 1g of (NH4)2SO4; 0.1g of MgSO4; 0.02g of CaCl2; 10g of glucose; trace elements mix; 1000mL of distilled water; adjust to pH 7.
The reaction will be exergonic.
To calculate the free energy (ΔG0′) of a reaction, you can subtract the free energies of formation (Gf0) of the reactants from those of the products. Given the following data, what will be true of this reaction? C6H12O6 + O2 → CO2 + H2O Gf0 : -917.3 0 -394.4 -237.2
whether there will be a requirement or production of energy.
The change in Gibbs free energy for a particular reaction is MOST useful in determining
exergonic and energy will be released
If ΔG0′ is negative, the reaction is
false
Free-energy calculations are dependent on the rates of the reactions.
The inhibitor binds to the enzyme in a location other than the active site, changing the shape of the active site.
How does a noncompetitive inhibitor reduce an enzyme’s activity?
No change in enzyme activity would be observed.
What would be the likely outcome if you increased the concentration of substrate for an enzyme in the presence of a noncompetitive inhibitor?
It alters the active site of reverse transcriptase, decreasing that enzyme’s activity.
How is nevirapine used to treat HIV infections?
They compete with the substrate for the enzyme’s active site.
How does a competitive inhibitor slow enzyme catalysis?
Competitive inhibitors have structures that resemble the enzyme’s substrate.
What enables competitive inhibitors to bind to a specific enzyme?
The enzyme will stop functioning.
If high amounts of sulfanilamide are in the presence of an enzyme whose substrate is PABA, what outcome is expected?
Competitive inhibitors decrease the rate of enzyme activity.
Which of the following statements regarding competitive inhibitors is true?
Energy is required to disrupt a substrate’s stable electron configuration.
Why do all enzymatic reactions need activation energy?
Enzymes speed up the chemical reactions in living cells.
What is meant by the statement “Enzymes are biological catalysts”?
Enzymes decrease the amount of activation energy required for chemical reactions to occur.
Why are enzymes important to biological systems?
reducing the rate of a reaction to allow for better control
The role of an enzyme includes all EXCEPT which of the following?
required to transform all reactants into their reactive state.
Activation energy is the energy
changes the rate of the reaction but does not change the end amount of products.
A catalyst
active site
The portion of an enzyme to which substrates bind is referred to as the
Coenzymes are weakly bound whereas prosthetic groups are strongly bound to their respective enzymes.
What is the difference between a coenzyme and a prosthetic group?
a redox reaction
A reaction that involves the transfer of electrons from one molecule to another is referred to as
the donor molecule loses an electron and becomes oxidized.
During an oxidation reaction,
The electron acceptor’s net charge decreases.
Why is reduction the term used to describe the gain of an electron?
Redox reactions involve an oxidation reaction coupled with a reduction reaction.
Which of the following statements regarding redox reactions is true?
the greater the change in free energy (ΔG0′), and the greater the energy released
The reduction potential (E0′) of a substance reflects its tendency to donate or accept electrons. The larger the difference (ΔE0′) between the reduction potentials of the electron donor and the electron acceptor, __________.
a way to increase the types of redox reactions that occur in the cell by acting as an intermediary between dissimilar compounds
The function of NAD+/NADH in the cell is best described as __________.
simultaneous reduction of a different compound will also occur, because electrons do not generally exist alone in solution.
If an oxidation reaction occurs
true
If a substance is reduced, it gains electrons.
false
Due to the number of phosphate groups, ATP has approximately three times more energy stored than AMP, and ADP has approximately two-thirds the energy stored of ATP.
The majority of organisms obtain their carbon from organic sources.
Which statement below demonstrates why the majority of organisms are heterotrophs?
C2H3O2-
Which of the following would be used by a chemoorganotroph for energy?
carbon
A chemoorganotroph and a chemolithotroph in the same environment would NOT compete for
carbon and oxygen
A chemoorganotroph and a photoautotroph in the same environment would NOT compete for
acetate, succinate, and glucose
For a carbon source, chemoorganotrophs generally use compounds such as
