energy the ultimate source of all energy on earth
Post on 22-Dec-2015
220 views
TRANSCRIPT
![Page 1: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/1.jpg)
Energy
The ultimate source of all energy on Earth
![Page 2: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/2.jpg)
The Addition of Energy was important in early chemical
evolution
• Energy = the capacity to do work– Potential energy = stored energy– Kinetic energy = energy of motion– Other types of energy = thermal, sound,
mechanical, light, etc.
![Page 3: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/3.jpg)
3. When the molecule strikes the rocks below, its kinetic energy is converted to thermal, mechanical, and sound energy.
1. A water molecule sitting at the top of a waterfall has a defined amount of potentialenergy, Ep.
2. As the molecule falls, this stored energy is converted tokinetic energy, Ek.
Mechanical energy
Heat Sound
Ep (lower)
Ek
Ep (higher)ENERGY TRANSFORMATION IN A WATERFALL
![Page 4: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/4.jpg)
Newton’s First Law of Thermodynamics
• Energy is never created or destroyed, it is converted from one form to another
• The total amount of energy in a closed system remains the same
![Page 5: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/5.jpg)
Newton’s Second Law of Thermodynamics
• In a closed system, energy will transformation will always occur so that the entropy of the system will increase
• Entropy = random, useless energy that cannot do work, disorder, randomness
![Page 6: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/6.jpg)
Newton’s Second Law of Thermodynamics
• Living organisms are highly ordered
![Page 7: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/7.jpg)
Spontaneous changes within a system will occur to increase the entropy and free energy in a system
G = the quantity of energy in a system that can perform work
∆G = G final state - G starting state
![Page 8: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/8.jpg)
How do chemical reactions occur?
• Chemical reactions = the formation and breaking of chemical bonds:
Reactant + Reactant Products
AB + CD AC + BD
When the forward and back reactions occur at the same rate, the system is stable and is called a chemical equilibrium
![Page 9: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/9.jpg)
Example of an exergonic reaction: Burning methane
H
H
CH H CO OO O OH H Energy
2 WaterCarbon dioxide
OxygenMethane
Exergonic reactions release energy and occur spontaneously
![Page 10: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/10.jpg)
High-energy photon High-energy photon
HH
H O O
OO C
C
Endergonic reactions require the addition of energy
Energy + H2 H + H Energy + CO2 CO + O
![Page 11: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/11.jpg)
Energy changes in exergonic and endergonic reactions
![Page 12: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/12.jpg)
Free energy in chemical reactions
• The amount of free energy in a system depends on the entropy, temperature of the system:
G = H - TS
• The change in energy in a system is:
∆G = ∆H - T ∆GS
![Page 13: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/13.jpg)
To do work and power endergonic reactions, cells use ATP
![Page 14: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/14.jpg)
Coupling of exergonic and endergonic reactions
![Page 15: Energy The ultimate source of all energy on Earth](https://reader034.vdocuments.net/reader034/viewer/2022042717/56649d7a5503460f94a5f195/html5/thumbnails/15.jpg)
ATP is regenerated continuously
(cell respiration)