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26 Cards in this Set
- Front
- Back
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What are the three types of work accomplished by bacteria?
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Mechanical: movement of flagella & active transport of chemicals against a gradient.
Electrical: if movement in the gradient involves a charged molecule. Chemical: the constant synthesis of molecules, biosynthesis. |
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What is the quantity of energy necessary to raise the temperature of 1 kg of water 1° C?
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kcal
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What is an energy liberating process?
What is an energy requiring process? What is the free energy released in a rxn for work? |
Exergonic (delta G -7.3kcal)
Endergonic (delta G +3kcal) Delta G |
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What is stored energy? What is the energy of work and motion?
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Potential energy
Kinetic energy |
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What is the study of energy transformations?
What is the the study of energy transformations in living systems? |
Thermodynamics
Bioenergetics |
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What is the 1st Law of Thermodynamics?
The 2nd Law? |
Energy can neither be created or destroyed, it converts from one form to another.
All processes in the universe result in an increase in entropy or disorder. (unrecoverable energy) |
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How does a reversible chemical reaction occur?
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Rxns that continue until they reach an equilibrium point, a balance between reactants and products.
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What is the ratio of the concentrations of reactants and products?
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Equilibrium constant, Keq
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What is an enzyme? What does it do?
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They are proteins and catalysts that occur in living organisms.
An enzyme acts on a substrate, they lower the energy of activation for a reaction. |
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What is activation energy?
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The difference between the free energy of reactants and the highest free energy of reactants during their transition to product.
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Describe the equation for Thiosulfate cyanide sulfur transferase. What does SCN and S2O3 stand for?
What enzyme is involved in this reaction? What else does it do? |
S2O3 + CN --> SCN + SO4
SCN: thiocynate S2O3: thiosulfate rhodanese cynate interferes with ETC |
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What three areas influences enzymatic activity?
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pH, temperature and ionic strength
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Bacteria can be grown on media to make enzymes. What are techniques to isolate the enzymes? (3 steps)
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1. organic precipitation followed by column chromatography
2. purification increases but yield decreases 3. once purified, then look at the effect of pH, temp, ionic strength, Km |
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What is the model that describes the very specific interactions between the enzyme and substrate?
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Lock and key model
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Regulators of enzymes
What are reversible inhibitors? What are irreversible inhibitors? |
Reversible inhibitors can be competitive or noncompetitive.
Irreversible inhibitor can be silver nitrate because it binds... |
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What are competitive inhibitors? Name an example.
How are they reversible? Name an example |
Compete with the substrate with binding to the active site because of similar structure.
Ex: malonate inhibits Succinate dehydrogenase Reversible by increasing the substrate concentration. |
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T or F: Noncompetitive inhibitors are structurally related to the enzyme substrate, therefore increasing the substrate concentration has no effect.
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FALSE FOOL. They are NOT structurally related.
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What is a form of noncompetitive inhibition, where these allosteric enzymes have 2 binding sites, an active site where the substrate binds and a second site where the effectors bind?
Name an example |
Allosteric inhibition
ex: lac operon |
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What is feedback inhibition?
Where does it occur? |
An end product in a biosynthetic pathway inhibits a key enzyme early in the pathway.
Occurs in amino acid biosynthesis |
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Describe an example of feedback inhibition (in your own words...take a deep breath).
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MSG is made from bacteria. Mutagens inhibit feedback inhibition in C. glutanicum so more glutamate is produced.
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What are two other substances involved in enzymatic reactions and what do they do?
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Cofactors:often required for enzymatic activity, ions etc.
Organic cofactors: coenzymes that carry electrons |
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Where are coupled reactions seen?
What are examples of electrons carriers besides the ultimate electron acceptor? |
In redox reactions
Ex: NAD, NADP, FAD, FMN. |
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What is a reaction in which electrons are lost from a substance?
What is a reaction in which electrons released from a substance are accepted by another compound? |
Oxidation
Reduction |
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What are three ways that microbial metabolism can be utilized?
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Can be used for cleanup, food production, antibiotics, etc.
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Substances differ in their abilities to donate or accept electrons. This is measurable and becomes the...
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redox potential, (E0)
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Describe the process of bioremediation (take a deep breathe and describe slowly...)
What chemical is removed up in this process? This is an example of a... |
Pseudomonas are gram negative rods which can use anaerobic respiration using nitrate.
So pseudomonas plus nitrate are injected into groundwater through wells; they use the NO3 electron acceptor and it turns into N2; also CO2 and H2O are formed Can cleanup perchloroethylene that was used by dry cleaners Example of a redox potential |
