Test 2 Flashcards
First Law of Thermodynamics
Energy cannot be created nor
destroyed, but can be transformed
Second Law of Thermodynamics
Disorder always increases (+ ∆S)
∆H<0
Exothermic
∆H>0
endothermic
∆G<0
Exergonic
∆G>0
Endergonic
The higher the activation energy “hump” the _ the reaction
slower
provides alternative reaction pathway with lower activation energy
catalyst
_ increases the rate of a reaction
catalyst
Catalysts cannot do what
cannot change equilibrium position, cannot change Delta G or free energy of reaction
The higher G°‡ the _ the reaction
slower
catalyst lower_and speed up reaction
G°‡
G° equation
ΔG° = - RT ln Keq
what is zero order kinetics
rate does not depend on concentration of substrate
what is first order kinetics
rate depends on concentration of substrate
Michaelis-Menten equation
V0= (V max [S])/(KM + [S]). Vmax or Vm is the max velocity of the enzyme. KM is the steady-state constant or Michaelis constant
KM equation
KM= [S] at Vmax/2
at [S] , KM-> low V init
enzyme not very active
at [S] <KM-> high V init</KM->
enzyme more active
what is Km
substrate concentrate at 1/2 Vmax
what is Km
concentration of substrate at cellular concentration in most cases
Different substrates of the same enzyme have different?
Km
Low values of Km indicate ?
tighter binding affinity
Michaelis Menten cure can be transformed into ?
a straight line
what is a reversible inhibition
an inhibitor that binds to and dissociates from an enzyme form reaching equilibrium
what are the most common ways enzymes are regulated
cellular regulators, drugs
what are the types of reversible inhibition
competitive, non competitive
job of competitive inhibition
S competes with inhibitor I for active site on E ➔ either S or I binds to E ➔ more
substrate required to reach a given reaction velocity
job of noncompetitive inhibition
Inhibitor can bind to E or ES; S can bind to E or EIDifferent binding sites!
is is the branch of thermodynamics that deals with
living organisms
bioenergetics
total heat content (delta H)
enthalpy
three factors that effect bioenergetic/biochemical reactions
enthalpy, entropy, free energy
state of disorder (delta S)
entropy
energy available to do chemical work
free energy
predictor of spontaneity (delta G)
free energy
first law of thermodyanamics
Energy cannot be created nor
destroyed, but can be transformed
second law of thermodynamics
Disorder always increases (+delta S)
third law of dynamics
As the temperature of a perfect crystalline solid approaches absolute zero, disorder (S) approaches zero (0ºK or -273ºC)
exothermic meaning
gives off heat (negative delta H)
endothermic meaning
absorbs heat (positive delta H)
exothermic or endothermic reactions are ones that are often favored?
exothermic-but cannot be used to predict the direction of reactions
physical or chemical changes resulting in a realse of energy are?
spotaneous
_reactions require constant energy output
non-spontaneous
_is the missing factor to determine the direction of a reaction
entropy-delta S
All spontaneous processes occur in the direction that increases _
disorder (deltaS >0)
_ is the measure of disorder of a system
entropy
more disorder the higher the _
entropy-drives reactions
_is the combination of first and second laws of thermodynamics
Free energy (G)
delta G equation
delta G= delta H - T delta S
three possible values for free energy _
negative, positive, zero
reaction is favorable when delta G is less than _
zero
when reaction the negative heat term (delta H) is dominant, the reaction is _ driven
enthalpy
if _ is more dominant, the reaction is entropy driven
T delta S
are endergonic reactions spotaneous or non
non spontaneous
delta G is greater than zero in what reactions
endergonic
what reaction is unfavorable thermodynamically
endergonic
what reaction is reverse reaction favored
endergonic
metabolism has how many branches
two-anabolism, catabolism
what is anabolism
large, complex molecules synthesized from smaller precursors
what does anabolism require
requires enrgy (ATP and NADPH are the energy sources)
Catabolism is what
large, complex molecules degraded into smaller, simpler product
_releases energy
catabolism
anaerobic process that does not need O2
Glycolysis
_occurs in almost every living cell
Glycolysis
ancient process central to all life
glycolysis
spllit glucose intwo three-carbon pyruvate units
glucose catabolism-glycolysis
catabolic process that captures some energy as 2 ATP and 2 NADH
glucose catabolism-glycolysis
where does the Kreb Cycle occur
Mitochondria
in the Kreb Cycle, cytosolic pyruvate must cross two membrane of_
mitochondria
Outer membrane can be crossed using_ in the Kreb Cyle
porins
Inner membrane can be crossed using _ in the Kreb Cycle
transport proteins
three process in aerobic metabolism
citric acid cycle, electron trasport chain, and oxidative phosphorylation
what are the intermediates of aerobic metabolism
NADH, FADH2, FMN, FAD
