Energy - The ability to do work Needed by all living things There are different forms of energy...
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Thermodynamics and Biology
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Transcript of Energy - The ability to do work Needed by all living things There are different forms of energy...
Thermodynamics and Biology
Energy - The ability to do work• Needed by all living things• There are different forms of energy • Light
• Heat
• Electrical
• Sound
Energy for building up – Anabolic Reaction
Energy for breaking down – Catabolic Reaction
Metabolism is the sum of all anabolic and catabolic reaction in a cell or organism.
All energy can be grouped into either kinetic or potential energy.
#1 Kinetic Energy The energy possessed by moving
objectsex Thermal (random motion of
particles) Mechanical (coordinated motion of
particles) Electrical (motion of charged
particles)
#2 Potential Energy
Stored energyUsually due to position
within an attractive or repulsive force field
ex gravitational potential energy – the attraction between 2 objects
ex chemical potential energy
– the attraction of electrons- and protons+ in a chemical bond
Thermodynamics – the study of energy transformations in living and non-living systems
First Law of Thermodynamics(Law of Conservation of Energy)
Energy cannot be created or destroyed, but only converted from one form to another.
The total amount of energy in the universe is constant.
Energy in nature is not always readily available.Organisms must convert it from one form to another.
PhotosynthesisSun light energy plants chemical potential energy
glucose
Cellular respirationglucose energy passed on to ATP (energy-transferring compound in
living things)
Bond Energy
equals the amount of energy needed to break on mole (6.02 x 1023) of bonds
also a measure of stability of covalent bonds
ex H-H = 436 kJ/molC=O = 799 kJ/mol (more
stable)
In chemical reactions: If reactant bonds broken – energy absorbed If product bonds formed – energy released
Activation Energy: energy needed to strain and break reactant bonds
Transitional State: the temporary state where reactant bonds are breaking and product bonds are forming
Endothermic / Endergonic Reaction: the energy of the products is higher than the energy of the reactants
Exothermic / Exergonic Reaction: the energy of the reactants is higher than the energy of the products
Endothermic / Endergonic Reaction
Transition State
Products
Reactants Net amount of energy gained
Activation Energy
Ch
em
ical
Pote
nti
al
En
erg
y
Progress of Reaction
Exothermic / Exergonic Reaction
Transition State
Products
Reactants
Net amount of energy lost
Activation Energy
Ch
em
ical
Pote
nti
al
En
erg
y
Progress of Reaction
Entropy – a measure of randomness or disorder of objects or energyEntropy increases when disorder
increases.
Entropy increases when:1. A few number of reactant molecules
produce a large number of product molecules
2. Solid reactants become liquid products
3. Liquid reactants become gaseous products
