Questions and Well Defined
Answers.
Metabolism - ANSWER is the total of all chemical reactions in the cell and is divided
into two parts:
-Catabolism
-Anabolism
Catabolism - ANSWER Metabolic pathways that break down molecules, releasing
energy.
-fueling reactions
-energy-conserving reactions
-provide ready source or reducing power(electrons)
-generates precursors for biosynthesis
Anabolism - ANSWER Metabolic pathways that construct molecules, requiring
energy.
-the synthesis of complex organic molecules from simpler ones
-requires energy from fueling reactions
How many transformations does the nitrogen cycle have? - ANSWER -It has 8
transformations
-4 are solely done by microbes. However, microbes are part of the other 4
Chemical Work - ANSWER Synthesis of complex molecules
Transport Work - ANSWER Take up nutrients, elimination of wastes, and
maintenance of ion balances
Mechanical Work - ANSWER cell motility and movement of structures within cells
What is thermodynamics? - ANSWER -A science that analyzes energy changes in
a collection of matter called a system, such as a cell
-All other matter in the universe is called the surroundings
first law of thermodynamics - ANSWER Energy can neither be created NOR
destroyed
-total energy in universe remains constant
,UCF Microbiology EXAM 3 With
Questions and Well Defined
Answers.
-However, energy may be redistributed either within a system or between the system
and its surroundings
Second Law of Thermodynamics - ANSWER Physical and chemical processes
proceed in such a way that the disorder of the universe increases to the maximum
possible
-entropy=amount of disorder in a system
Entropy - ANSWER Amount of disorder in a system
Calorie (cal) - ANSWER amount of heat energy needed to raise 1 gram of water
from 14.5 C to 15.5C
Joules (J) - ANSWER Units of work capable of being done by a unit of energy
1 calorie=4.184J
Change in Free energy equation - ANSWER ΔG = ΔH - TΔS
-Expresses the change in energy that can occur in chemical reactions and other
processes
Note:
ΔG= free energy change, amount of energy available to do work
ΔH = change in enthalpy
T= Temp in Kelvin
ΔS= change in entropy
ΔG - ANSWER free energy change, amount of energy available to do work
ΔH - ANSWER Change in enthalpy
ΔS - ANSWER Change in entropy
If ΔG is negative, then the reaction is___? - ANSWER Spontaneous and exergonic
If ΔG is positive, then the reaction is___? - ANSWER not spontaneous and
Endergonic
,UCF Microbiology EXAM 3 With
Questions and Well Defined
Answers.
When is a reaction at equilibrium? - ANSWER When the rate of forward rxn=rate of
reverse rxn
Standard Free Energy Change (ΔG^o') - ANSWER (ΔG^o') is the free energy
change defined at standard conditions of concentration, pressure, temperature, and
pH
AMP - ANSWER adenosine monophosphate (1 phosphate)
ADP - ANSWER adenosine diphosphate(2 phosphates)
Exergonic break down of high energy ATP is coupled with _____ reactions to make
them more favorable - ANSWER endergonic
Exergonic Reactions - ANSWER Chemical reactions that releases energy
Endergonic Reaction - ANSWER Reaction that absorbs free energy from its
surroundings.
GTP - ANSWER Guanosine-5'-Triphosphate.
-Used for RNA transcription as the energy source. will become GDP when used.
CTP - ANSWER cytosine 5'-triphosphate
UTP - ANSWER Uridine 5'Ttriphosphate
ATP - ANSWER (adenosine triphosphate) main energy source that cells use for
most of their work
-Has a high phosphate transfer potential, which means that its readily able to send
phosphates to other molecules. However, it doesn't have the highest phosphate
transfer potential.
substrate-level phosphorylation (SLP) - ANSWER The formation of ATP by directly
transferring a phosphate group to ADP from an intermediate substrate in catabolism.
Oxidation-Reduction reaction - ANSWER any chemical change in which one
species is oxidized (loses electrons) and another species is reduced (gains
electrons); also called redox reaction
NOTE:
LEO(Lose Electrons Oxidation)
GER(Gain Electrons Reduced)
, UCF Microbiology EXAM 3 With
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Answers.
or
OIL (Oxidation is Lose)
RIG (Reduction is Gain)
Electron Carries - ANSWER are often used to transfer electrons from an electron
donor to an electron acceptor, which can result in energy release, which can be
conserved and used to form ATP
-The more electrons a molecule has, the more energy rich it is
-Glucose can donate up to 24 electrons
Oxidizing reaction - ANSWER electron donating/losing
Reducing reaction - ANSWER electron accepting/gaining
Conjugate Redox pair - ANSWER acceptor and donor of a half reaction
Standard redox potential - ANSWER Eo
-Equilibrium constant for an oxidation-reduction reaction
-Given in Volts
-A measure of the tendency of the reducing agent to lose electrons
A more negative Eo =_____? - ANSWER Better electron donor (Reducing
agent/reductant)
A more positive Eo=______? - ANSWER Better electron acceptor (Oxidizing
agent/Oxidant)
2 Rules of Redox pairs - ANSWER 1. When writing a redox couple, the reduced
member of the pair that is more negative donates electrons to the oxidized member
of the pair that is more positive
2. The greater the difference in redox potential (ΔE^o') between the redox pairs that
serves the electron donor and the acceptor, the greater the amount of energy
available (ΔG^o') in the oxidation-reduction reaction
Substances being oxidized, is the_____? - ANSWER Electron donor/reducing
agent/reductant