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Chapter 8 Pictures . Potential and Kinetic Energy. 2 nd Law of Thermodynamics. Kinetic Energy 25% drives the pistons 75% lost as heat. Potential Energy-Fuel. *In every chemical reaction, some energy is lost as heat . Enzyme 1. Enzyme 2. Enzyme 3. A. D. C. B. Reaction 1. - PowerPoint PPT Presentation
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Chapter 8 Pictures
Potential and Kinetic Energy
2nd Law of Thermodynamics
Potential Energy-Fuel Kinetic Energy 25% drives the pistons75% lost as heat
*In every chemical reaction, some energy is lost as heat.
Theoretical metabolic pathway
Enzyme 1 Enzyme 2 Enzyme 3A B C D
Reaction 1 Reaction 2 Reaction 3Startingmolecule
Product
Fig 5.2. Catabolic vs. Anabolic Reactions
• Condensation → reactions (anabolic)
• Hydrolysis → reactions (catabolic)
• Catabolic Rxns – • O-O O + O + Energy
• Anabolic Rxns-O + O + Energy O-O
Figure 8.6
In exergonic rxns∆G is a negative
number
ALL rxns require some input of energy
Fig 8.14 Energy Profile for a Catabolic (Exergonic) Reaction
Question 8.1
Example 1: Baking soda + vinegar (fast reaction)
fructose + glucose
Example 2: Sucrose hydrolysis (very slow reaction)
+ H2O
Examples of an exergonic and endergonic reaction
Glutamine
+
Glutamic Acid Ammonia
ΔG = - 3.4 kcal/mol
Glutamine
+
Glutamic AcidAmmonia
ΔG = + 3.4 kcal/mol
Chemical Equilibrium
An organism in metabolic equilibrium
Equilibrium
ATP
ATP
Metabolic Disequilibrium
ATPATP
Food
Waste Products
Fig 8.3
Chapter 8-ATP
ATP = Currency of the Cell
Fig 8.11
Fig 8.9 ATP hydrolysis
Fig 8.8
Coupled Reactions
Fig 8.10ATP hydrolysis
ATP synthesis
Question 8.2
Chapter 8 - Enzymes
Fig 8.13. Enzyme-catalyzed reaction: hydrolysis by sucrase
Metabolic Map
Fig 8.13. Enzyme-catalyzed reaction: hydrolysis by Sucrase
Fig 8.14Energy Profile
Energy (heat)absorbed from the surroundings
Energy (heat)released by the reaction
Fig 8.15 Energy Profile +/- Enzyme
Progress of the reaction
Products
Course of reaction without enzyme
Reactants
Course of reaction with enzyme
EA
withoutenzyme
EA with enzymeis lower
∆G is unaffected by enzymeFr
ee e
nerg
y
Fig 8.17
Fig 8.16
Fig 8.18aOptimal temperature for enzyme of thermophilic
Rat
e of
reac
tion
0 20 40 80 100Temperature (Cº)
(a) Optimal temperature for two enzymes
Optimal temperature fortypical human enzyme
(heat-tolerant) bacteria
Fig 8.18bR
ate
of re
actio
n
(b) Optimal pH for two enzymes
Optimal pH for pepsin (stomach enzyme) Optimal pH
for trypsin(intestinalenzyme)
10 2 3 4 5 6 7 8 9
Question 8.3
Fig 8.19 a, b
Figure 8.19 (b) Competitive inhibition
A competitiveinhibitor mimics the
substrate, competingfor the active site.
Competitiveinhibitor
A substrate canbind normally to the
active site of anenzyme.
Substrate
Active site
Enzyme
(a) Normal binding
Fig 8.19c
Figure 8.19
A noncompetitiveinhibitor binds to the
enzyme away fromthe active site, altering
the conformation ofthe enzyme so that its
active site no longerfunctions.
Noncompetitive inhibitor
(c) Noncompetitive inhibition
Fig 8.21
Question 8.4