Thermodynamics and Metabolism Slide 2 Metabolism = Catabolism +
Anabolism Catabolic reactions are energy yielding breakdown of
more-complex molecules into simpler ones Anabolic reactions are
energy requiring building up of simpler molecules into more-
complex ones Metabolism Slide 3 Slide 4 1 st : Energy can be
transferred or transformed but neither created nor destroyed. 2 nd
: Every energy transfer or transformation increases the disorder
(entropy) of the universe. Note especially the waste heat First and
Second Laws of Thermodynamics Slide 5 Organisms take in energy
& transduce it to new forms (1st law) As energy transducers,
organisms are less than 100% efficient (2nd law) Energy in the
Biosphere Slide 6 Organisms employ this energy to: Grow Protect
Themselves Repair Themselves Compete with other Organisms Make new
Organisms (i.e., babies) Slide 7 In the process, organisms generate
waste chemicals & heat Organisms create local regions of order
at the expense of the total energy found in the Universe!!! We are
Energy Parasites! Slide 8 Kinetic and Potential Energy Slide 9
First Law of Thermodynamics: Energy can be neither created nor
destroyed Therefore, energy generated in any system is energy that
has been transformed from one state to another (e.g., chemically
stored energy transformed to heat) Slide 10 Second Law of
Thermodynamics: Efficiencies of energy transformation never equal
100% Conversion to heat is the ultimate fate of chemical energy
Slide 11 Downhill Increase stability Greater entropy G < 0 Slide
12 Potential energy Work SpontaneousFood Forward reaction Waste
heat Slide 13 Types of Reactions Slide 14 Energy released Food
Movement toward equilibrium 1. Exergonic Reactions Slide 15
Decrease in Gibbs free energy (- G) Increase in stability
Spontaneous (gives off net energy upon going forward) Downhill
(toward center of gravity well, e.g., of Earth) Movement towards
equilibrium Coupled to ATP production (ADP phosphorylation)
Catabolism Slide 16 Energy required Work 2. Endergonic reactions
Slide 17 Decrease in stability Not Spontaneous (requires net input
of energy to go forward) Movement away from equilibrium Coupled to
ATP utilization (ATP dephosphorylation) Anabolism Slide 18 Slide 19
Coupling Reactions Exergonic reactions can supply energy for
endergonic reactions Slide 20 Energy Coupling in Metabolism
Catabolic reaction Anabolic reaction Catabolic reactions provide
the energy that drives anabolic reactions forward Slide 21
Adenosine Triphosphate (ATP) Slide 22 Energy Coupling via ATP Slide
23 Hydrolysis of ATP Slide 24 Various Pi Transfers Slide 25 Summary
of Metabolic Coupling Endergonic reaction Exergonic reaction
Endergonic reaction Exergonic processes drive Endergonic processes
Slide 26 Electron Carriers Compounds that pick up electrons from
energy- rich compounds and donate them to low-energy compounds
Redox reaction: LEO the lion says GER Slide 27 Electrons that pass
from one to another carry energy with them, so the reduced form of
a molecule is always at a higher energy level than the oxidized
form Slide 28 Anabolic process Catabolic process Chemically stored
energy Slide 29 Slide 30 The End
