Post on 22-Mar-2020
Figure 8-01
LE 8-UN141
Enzyme 1
A B
Reaction 1
Enzyme 2
C
Reaction 2
Enzyme 3
D
Reaction 3
ProductStarting
molecule
LE 8-2On the platform,the diver hasmore potentialenergy.
Diving convertspotentialenergy to kinetic energy.
Climbing up convertskinetic energy ofmuscle movement topotential energy.
In the water, the diver has lesspotential energy.
LE 8-3
Chemical
energy
Heat CO2
Primera Ley de la Termodinámica b) Segunda Ley de la Termodinámica
H2O
LE 8-4
50 µm
LE 8-5
Movimiento gravitatorio Difusión Reacción Química
LE 8-6
Reactivos
Reactivos
Energía
Energía
Productos
Productos
Progreso de la reacción
Progreso dela reacción
Cantidad
De energía
liberada
(G < 0)
Cantidad de
Energía
liberada
(G < 0)
En
erg
ía lib
rey
En
erg
ía lib
re
Reacción enedergónica: energía requerida
Reacción exergónica: energía liberada
LE 8-6a
Reactants
Energy
Products
Progress of the reaction
Amount of
energy
released
(G < 0)
Fre
e e
nerg
y
Exergonic reaction: energy released
LE 8-6b
Reactants
Energy
Products
Progress of the reaction
Amount of
energy
required
(G > 0)
Fre
e e
nerg
y
Endergonic reaction: energy required
LE 8-7a
G = 0
Un sistema hidroeléctrico cerrado
G < 0
LE 8-7b
Un sistema hidroeléctrico abierto
G < 0
LE 8-7c
Un sistema hidroelétrico de múltiples pasos
G < 0
G < 0
G < 0
LE 8-8
Phosphate groups
Ribose
Adenine
LE 8-9
Adenosine triphosphate (ATP)
Energy
P P P
PPP i
Adenosine diphosphate (ADP)Inorganic phosphate
H2O
+ +
LE 8-10
Endergonic reaction: G is positive, reactionis not spontaneous
Exergonic reaction: G is negative, reactionis spontaneous
G = +3.4 kcal/mol
G = –7.3 kcal/mol
G = –3.9 kcal/mol
NH2
NH3Glu Glu
Glutamicacid
Coupled reactions: Overall G is negative;together, reactions are spontaneous
Ammonia Glutamine
ATP H2O ADP Pi
+
+ +
LE 8-11
NH2
Glu
P i
P i
P i
P i
GluNH3
P
P
P
ATP
ADP
Motor protein
Mechanical work: ATP phosphorylates motor proteins
Protein moved
Membrane
protein
Solute
Transport work: ATP phosphorylates transport proteins
Solute transported
Chemical work: ATP phosphorylates key reactants
Reactants: Glutamic acidand ammonia
Product (glutamine)made
+ +
+
LE 8-12
Pi
ADP
Energy for cellular work
(endergonic, energy-
consuming processes)
Energy from catabolism
(energonic, energy-
yielding processes)
ATP
+
LE 8-13
Sucrose
C12H22O11
Glucose
C6H12O6
Fructose
C6H12O6
LE 8-14
Estado de transic0n
C D
A B
EA
Productos
C D
A B
G < O
Progreso de la reacción
Reactivos
C D
A B
En
erg
ía l
ibre
LE 8-15
Course of
reaction
without
enzymeEA
Sin enzima
G no se ve
Afectada por la
enzima
Progress of the reaction
Fre
e e
nerg
y
La EA con
Una enzimaEs mas baja
Desarrollo de
Reacción con
Una enzima
Reactants
Products
LE 8-16
Sustrato
Sitio activo
Enzyme Enzyme-substratecomplex
LE 8-17
Enzyme-substrate
complex
Substrates
Enzyme
Productos
los sustratos entran al sitio activo; la
Enzima cambia de forma de modo que
Su sitio activo abraza al sustrato (ajuste
Inducido)
los sustratos son
mantenidos en el sitio
activo por interacciones
débiles como puentes d
de H y enlaces iónicos.
El sitio activo (y los grupos
R de sus aminoácidos) pueden
La Ea y acelerar la reacción al:
Actuar como molde para la
Orientación del sustrato
Tensar los sustratos y estabi
lizar el estado de transición
Suministrar un microambiente
favorable
Participación directamente en
la reacción catalítica
los sustratos se
Convierten a
productos
se liberan los
productos.
el sitio
activo queda
disponible
para dos
nuevas
moléculas
de sustrato.
LE 8-18
Optimal temperature for
typical human enzymeOptimal temperature for
enzyme of thermophilic
(heat-tolerant
bacteria
Temperature (°C)
Optimal temperature for two enzymes
0 20 40 60 80 100
Optimal pH for pepsin
(stomach enzyme)Optimal pH
for trypsin
(intestinal
enzyme)
pH
Optimal pH for two enzymes
0 1 2 3 4 5 6 7 8 9 10
LE 8-18a
Optimal temperature for
typical human enzymeOptimal temperature for
enzyme of thermophilic
(heat-tolerant
bacteria
Temperature (°C)
Optimal temperature for two enzymes
0 20 40 60 80 100
LE 8-18b
Optimal pH for pepsin
(stomach enzyme)Optimal pH
for trypsin
(intestinal
enzyme)
pH
Optimal pH for two enzymes
0 1 2 3 4 5 6 7 8 9 10
LE 8-19
Substrate
Active site
Enzyme
Competitiveinhibitor
Normal binding
Competitive inhibition
Noncompetitive inhibitor
Noncompetitive inhibition
A substrate can
bind normally to the
active site of an
enzyme.
A competitive
inhibitor mimics the
substrate, competing
for the active site.
A noncompetitive
inhibitor binds to the
enzyme away from the
active site, altering the
conformation of the
enzyme so that its
active site no longer
functions.
LE 8-19a
Sustrato
Sitio activo
Enzima
Unión normal
Un sustrato puede
unirse normalmente
al sitio activo de una
enzima.
LE 8-19b
Inhibidor competitivo
Inhibición competitiva
Un inhibidor competitivo
imita al sustrato, y
compite por el sitio
activo.
LE 8-19c
Inhibidor no competitivo
Inhibición no competitiva
Un inhibidor no compe
titivo se une a la enzima
en un sitio distinto del
sitio activo y altera su
conformación de modo
que su sitio activo ya
no funciona .
LE 8-20a
Allosteric enzyme
with four subunits
Regulatory
site (one
of four)Active form
Activator
Stabilized active form
Active site
(one of four)
Allosteric activator
stabilizes active form.
Non-
functional
active siteInactive form
InhibitorStabilized inactive
form
Allosteric inhibitor
stabilizes inactive form.
Oscillation
Allosteric activators and inhibitors
LE 8-20b
Substrate
Binding of one substrate molecule to
active site of one subunit locks all
subunits in active conformation.
Cooperativity another type of allosteric activation
Stabilized active formInactive form
LE 8-21
Active siteavailable
Initial substrate(threonine)
Threoninein active site
Enzyme 1(threoninedeaminase)
Enzyme 2
Intermediate A
Isoleucineused up bycell
Feedbackinhibition Active site of
enzyme 1 can’tbindtheoninepathway off
Isoleucinebinds toallostericsite
Enzyme 3
Intermediate B
Enzyme 4
Intermediate C
Enzyme 5
Intermediate D
End product(isoleucine)
LE 8-22
Mitochondria,sites of cellular respiration
1 µm
LE 8-UN159
OML
N
S
R
Q
P–
–
–