• Lipids (fats)
• Carbohydrates (sugar)
• Protein
ENERGY• 1st Law of Thermodynamics
– Energy can’t be created or destroyed, it can only change forms.
chemical→ mechanical
chemical → mechanical
heat → mechanical electrical → mechanical
Photosynthesis
6 CO2 + 6H2O + energy→ C6H12O6 + 6O2
Metabolism
• Metabolism = The sum of all reactions occurring in an organism
– Catabolism – reactions involved in the breakdown of biomolecules; release heat/energy
– Anabolism – reactions involved in the synthesis of biomolecules; absorb heat/energy
.
ANABOLIC
CATABOLIC
Metabolism– Metabolism is the sum of catabolism and
anabolism.
oxidation and the release of energy
Triglycerides Proteins
Fatty acidsand glycerol
Amino Acids
Small molecules
Anabolismof proteins
beakdown of larger molecules to smaller ones
Some nutrients and products of catabolism
Products of anabolism, including proteins and
nucleic acids
Catabolism Excretion
energy andreducing agents
Monosac-charides
Polysac-charides
ExcretionAnabolism
Catabolism Anabolism
Free Energy (G)
A + B → C
A + B
C
Fre
e En
ergy
(G)
5
10
If A + B has more free energy than C, then the change in free energy (G) is negative. Product (C) – Reactants (A + B) 5-10 = -5
If energy is given off in a reaction; G is negative; favorable; catabolic
A + B → C
C
A + B
Fre
e En
ergy
(G)
5
10
If A + B has less free energy than C, then the change in free energy (G) is positive. Product (C) – Reactants (A + B) 10-5 = +5
If energy is absorbed in a reaction; G is positive; unfavorable; anabolic
6 CO2 + 6H2O + energy→ C6H12O6 + 6O2
PHOTOSYNTHESIS
G = +686 kcal energy
Free E
nergy (G
)
6 CO2 + 6 H2O
C6H12O6 + 6 O2
686
CATABOLISM OF FOOD
ATP = Adenosine Triphosphate
(G)Products – (G)Reactants = G [ADP + P] - ATP G = -7.3 kcal
Fre
e En
ergy
(G)
ATP
ADP + P
7.3 kcal
ATP → ADP + P
ATP → ADP + P + energy
7.3 kcal7.3 kcal
ADP + P + energy → ATP
Energy is given off;G is negative
Energy is absorbed; G is positive
MITOCHONDRIA
Metabolism = The sum of all reactions occurring in an organism
• Goal is to couple reactions that give off energy with those that absorb energy
A + B → AB
AB is higher energy than A and B alone
G is positive; requires input of energy; unfavorable
ADP and P are lower energy than ATPG is negative; releases energy; favorable
ATP → ADP + P
Coupled Reactions
ATP → ADP + P
A + B → AB G = +4.3 kcal
G = -7.3 kcal
A + B + ATP → AB + ADP + P
Overall G for coupled reaction = -3.0 kcal
Coupled reaction would be FAVORABLE
G =-3.0
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