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Microbiology ch10
Introduction to Metabolism
67
Microbiology
Undergraduate 1
02/26/2016

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Term
__________ reactions capture energy from the organisms' energy source.
Definition
Catabolic
Term
________ is the total of all chemical reactions occurring in the cell.
Definition
Metabolism
Term
_______ reactions build new organic molecules from smaller inorganic and organic compounds.
Definition
Anabolic
Term
In thermodynamic studies, energy changes are analyzed in a collection of matter called a __________. All other matter in the universe is called the __________.
Definition
system; surroundings
Term
_________ is the science that analyzes energy changes in a collection of matter.
Definition
Thermodynamics
Term
A reaction in which the forward rate is equal to the reverse rate is said to be at __________.
Definition
equilibrium
Term
Cells must efficiently transfer energy from their energy-trapping systems to the systems actually carrying out work and also use various metabolic processes to replace the energy used in doing work. This is called the __________.
Definition
energy cycle
Term
In order for the cell to be able to input energy into necessary endergonic reactions, energy-generating processes such as photosynthesis, fermentation, and respiration are used to produce __________.
Definition
ATP
Term
Disruption of an enzyme's structure with loss of activity caused by extremes of pH, temperature, or other factors is called _________.
Definition
denaturation
Term
A molecule that binds to an enzyme at a location other than the active site and thereby alters the enzyme's shape, making it inactive or less active is a(n) __________ inhibitor.
Definition
noncompetitive
Term
A molecule that binds noncovalently to an enzyme at the active site and thereby prevents a substrate from binding and reacting is a(n) __________ inhibitor.
Definition
competitive
Term
The molecules formed by an enzyme-catalyzed reaction are called __________.
Definition
products
Term
The reacting molecules in an enzyme-catalyzed reaction are called __________.
Definition
substrates
Term
The __________ __________ is the substrate concentration needed for an enzyme to achieve half maximal velocity.
Definition
Michaelis constant (Km)
Term
A complex formed during a reaction that resembles both the substrates and the products is called the __________ state complex. 
transition
Definition
transition
Term
RNA molecules that have catalytic activity are known as ____________.
Definition
ribozymes
Term
Cells carry out three major types of work; which of the following involves the synthesis of macromolecules as well as the breakdown of substances for their energy? 

A. Chemical work.

B. Transport work.

C. Mechanical work.

D. None of these.
Definition
A. Chemical work.
Term
Cells carry out three major types of work; which of the following involves nutrient uptake and waste elimination? 
A. Chemical work.

B. Transport work.

C. Mechanical work.

D. None of these.
Definition
B. Transport work.
Term
Cells carry out three major types of work; which of the following involves energy for cell motility and the movement of structures within cells? 

A. Chemical work.

B. Transport work.

C. Mechanical work.

D. None of these.
Definition
C. Mechanical work.
Term
T/F
Energy can be redistributed within a collection of matter (called a system) or can be redistributed between the system and its surroundings.
Definition
True
Term
__________ is a measure of the randomness or disorder of a system. 

A. Entropy

B. Enthalpy

C. Free energy

D. Synergy
Definition
A. Entropy
Term
The __________ law of thermodynamics states that energy can be neither created nor destroyed. 

A. first

B. second

C. third

D. fourth
Definition
A. first
Term
The __________ law of thermodynamics states that physical and chemical processes occur in such a way that randomness (disorder) increases to a maximum. 

A. first
 B. second
 C. third
 D. fourth
Definition
B. second
Term
The amount of heat energy needed to raise 1 gram of water from 14.5C to 15.5C is called a(n) 

A. joule.
 B. calorie.
 C. erg.
 D. thermal unit.
Definition
B. calorie
Term
T/F
The numerical value of the free energy change indicates how fast a reaction will reach equilibrium.
Definition
False
Term
__________ is the total energy change that accompanies a chemical reaction. 

A. Entropy
 B. Enthalpy
 C. Free energy
 D. Synergy
Definition
B. Enthalpy
Term
For the reaction A + B C + D, the equilibrium constant (Keq) is defined as 

A. [A][B]/[C][D].

B. [C][D]/[A][B].

C. [A][D]/[B][C].

D. [B][C]/[A][D].
Definition
B. [C][D]/[A][B].
Term
The change in __________ is the amount of energy in a system that is available to do work. 

A. entropy

B. enthalpy

C. free energy

D. synergy
Definition
C. free energy
Term
T/F
The most commonly used practical form of energy used in cells is adenosine diphosphate.
Definition
False
Term
A reaction that releases energy is __________. 

A. exergonic

B. endergonic

C. impossible

D. none of the choices
Definition
A. exergonic
Term
T/F
Some endergonic reactions can be made to proceed forward if they are coupled to hydrolysis of one or more of the phosphates of ATP.
Definition
True
Term
The __________ is the electron acceptor in a redox reaction. 
A. reductant

B. oxidant

C. enzyme

D. product
Definition
B. oxidant
Term
The __________ is the electron donor in a redox reaction. 
A. reductant
 B. oxidant
 C. enzyme
 D. product
Definition
A. reductant
Term
The standard reduction potential of a redox reaction is a measure of the tendency of the __________ to __________ electrons. 

A. reductant; gain

B. reductant; lose

C. oxidant; gain

D. oxidant; lose
Definition
B. reductant; lose
Term
T/F
The equilibrium constant for a redox reaction is called the standard reduction potential.
Definition
True
Term
Which of the following is used as an electron carrier by living organisms? 

A. NAD+

B. NADP+

C. ubiquinone

D. all of the choices
Definition
D. all of the choices
Term
T/F
The electron transport chain is based on the principle that redox couples with more positive reduction potentials will donate electrons to couples with more negative potentials.
Definition
False
Term
T/F
One of the components used during photosynthetic electron transport is ferredoxin, a nonheme iron protein.
Definition
True
Term
Electron transport molecules that only transfer electrons include 

A. ubiquinone.

B. NADP.

C. FAD.

D. ferredoxin.
Definition
D. ferredoxin.
Term
Which of the following is not true about enzymes? 
A. Enzymes are catalysts that speed up reactions.

B. Enzymes are proteins that can be denatured by changes in pH or temperature.

C. Enzymes are highly specific for the substrates they react with and catalyze only one or a limited set of possible reactions with those substrates.

D. all of the choices
Definition
D. all of the choices
Term
T/F
Each enzyme normally has specific pH and temperature optima at which they function best.
Definition
True
Term
T/F
The Michaelis constant (Km) of an enzyme is the substrate concentration that produces maximum velocity.
Definition
False
Term
T/F
Enzyme activity can be greatly affected by the pH and the temperature of the environment in which the enzyme must function.
Definition
True
Term
T/F
When the amount of enzyme present is held constant, the rate of a reaction will continue to increase as long as the substrate concentration increases.
Definition
False
Term
T/F
Enzymes increase the rate of a reaction but do not alter equilibrium constants.
Definition
True
Term
T/F
Enzymes increase the rate of a reaction by increasing molecular motion, thereby providing kinetic energy to drive the reaction.
Definition
False
Term
Enzymes are usually named based on 

A. the substrates they act on.

B. their molecular structure.

C. the type of reaction they catalyze.

D. all of the choices.

E. the substrates they act on and the type of reaction they catalyze.
Definition
E. the substrates they act on and the type of reaction they catalyze.
Term
The most specific term usually used to describe a substance in a biological system that increases the rate of a reaction without being permanently changed by the reaction is a(n) 
A. catalyzer.

B. catalyst.

C. enzyme.

D. rate increaser.
Definition
C. enzyme.
Term
The substrate of an enzyme binds at the 

A. affinity site.

B. active site.

C. determinative site.

D. reaction site.
Definition
B. active site.
Term
A complete enzyme that consists of a protein component and a nonprotein component is called a(n) 

A. apoenzyme.

B. heteroenzyme.

C. holoenzyme.

D. multienzyme.
Definition
C. holoenzyme.
Term
A nonprotein component of an enzyme that is loosely attached to the protein component is referred to as a(n) 
A. apoenzyme.

B. coenzyme.

C. holoenzyme.

D. prosthetic group.
Definition
B. coenzyme.
Term
The nonprotein component of an enzyme that is firmly attached to the protein is called a(n) 

A. apoenzyme.

B. coenzyme.

C. holoenzyme.

D. prosthetic group.
Definition
D. prosthetic group.
Term
If an enzyme consists of a protein component and a non-protein component, the protein component is referred as the 
A. apoenzyme.

B. coenzyme.

C. holoenzyme.

D. prosthetic group.
Definition
A. apoenzyme.
Term
If all available enzyme molecules are binding substrate and converting it to produce as rapidly as possible, the reaction is said to be proceeding at __________ velocity. 

A. terminal

B. maximal

C. optimal

D. infinite
Definition
B. maximal
Term
A(n) _______________ increases the rate of a reaction without being permanently altered by the reaction. 

A. catalyzer
 B. catalyst
 C. enzyme
 D. rate increaser
Definition
B. catalyst
Term
Enzymes function as catalysts by 

A. bringing the substrates together at the active site, in effect concentrating them.

B. bringing the substrates together at the active site correctly oriented for the reaction.

C. bringing the substrates together at the active site, in effect concentrating them and bringing the substrates together at the active site correctly oriented for the reaction.

D. none of the choices
Definition
C. bringing the substrates together at the active site, in effect concentrating them and bringing the substrates together at the active site correctly oriented for the reaction.
Term
Enzymes catalyze a reaction by 

A. decreasing the amount of energy released by the reaction.
B. increasing the amount of energy released by the reaction.
C. decreasing the activation energy of the reaction.
D. increasing the activation energy of the reaction.
Definition
C. decreasing the activation energy of the reaction.
Term
The energy required to bring the substrates of a reaction together in the correct way to reach the transition state is called 

A. free energy.
 B. activation energy.
 C. enthalpy.
 D. entropy.
Definition
B. activation energy.
Term
T/F
One important ribozyme located in mitochondria is responsible for catalyzing peptide bond formation during protein synthesis.
Definition
False
Term
Which of the following is a reason for metabolic regulation? 
A. Maintain cell components at appropriate levels.

B. Conserve materials.

C. Ensure efficient use energy stores.

D. All of the choices.
Definition
D. All of the choices.
Term
In metabolic channeling, the regulation of metabolic pathways is controlled by the __________ of metabolites and enzymes involved in the pathway. 

A. amount
 B. location 
C. activity 
D. all of the choices
Definition
B. location
Term
Metabolic channeling involves the localization of __________ in different parts of a cell in order to influence the activity of metabolic pathways. 

A. activators 
B. repressors
 C. substrates and enzymes
D. inhibitors
Definition
C. substrates and enzymes
Term
When the end product of a pathway inhibits catalysis of the first step of that pathway, this phenomenon is called 
A. reversible covalent modification.

B. feedback inhibition.

C. metabolic channeling.

D. non-competitive inhibition.
Definition
B. feedback inhibition.
Term
Enzyme activity can be controlled by 

A. allosteric regulation.
 B. covalent modification.

C. feedback (end product) inhibition.
 D. all of the choices
Definition
D. all of the choices
Term
In allosteric regulation, effector molecules usually bind 
A. reversibly and covalently.

B. irreversibly and covalently.

C. reversibly and noncovalently.
D. irreversibly and noncovalently.
Definition
C. reversibly and noncovalently.
Term
In a branched pathway with many end products, an abundance of one of the end products will usually inhibit 
A. the first step in the set of pathways.

B. the first committed step in the branch of the pathway leading to the production of that particular product.

C. the last step before the branch leading to the production of that particular end product.

D. the last step in the production of that particular product.
Definition
B. the first committed step in the branch of the pathway leading to the production of that particular product.
Term
T/F
Isoenzymes are different enzymes that catalyze the same reaction but can be regulated independently of one another.
Definition
True
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