1. Energy: the Basics

2. Energy
The ability to do work

3. Nature of Energy
kilogram calorie (kcal or C): the amount of energy required to raise 1 kg water 1°C.
Nutrition
Ecology.
potential energy: stored energy.
Organisms – carbohydrates, ATP, fat or protein
kinetic energy: energy in motion.
Energy Transfers in Organisms
Photosynthesis
Respiration
Locomotion
Reproduction

4. Forms of Energy Mechanical: energy of motion Thermal
internal energy in substances
the vibration and movement of the atoms and molecules within substances.
Chemical: the energy stored and released in the bonds between atoms in a molecule.
Electrical: the energy that results from the motion of electrons.
Nuclear
the energy stored in the nucleus of an atom
released by splitting atoms (fission) or joining of atoms (fusion).
Electromagnetic:
energy that travels by waves
radio, infrared, visible light, UV, microwaves, X-Rays, and Gamma rays.

5. Units of Energy British Thermal Unit (btu)
1Btu = the amount of energy needed to raise the temperature of 1 pound of water by 1°F.
Joule: most countries use the Joule
1 joule = ft·lb
Calorie: amount of heat needed to raise the temperature of 1g of water 1°C. Food calories are Kilocalories.
Horsepower: automotive measurement: 1 HP = 746 Watt
Watt: unit of power, work-time
Electrical: the same as a Kilowatt-hour
the amount of energy expended by one kW device in 1 hour
what is used on the power bill every month.
Thermal: nuclear power plants produce heat measured in thermal watts.

6. THERMODYNAMICS
Thermodynamics: the study of energy transfer.
2 Laws

7. 1st Law of Thermodynamics
Energy is neither created nor destroyed, but is only transformed.
In any process, the total energy of a closed system remains constant.
You can't get something from nothing.

8. 2nd Law of Thermodynamics
Any closed system tends spontaneously toward increasing disorder (disordered energy = entropy).
In any energy conversion some energy is transferred to the surroundings as heat.
No real process can be 100% efficient.
There can never be a perpetual motion machine.

9. Ecological Energy Measuring the energy content in organisms
Strongly correlated with dry mass, which is correlated with wet mass.
The flow of energy is strongly related to the flow of matter.
An increase in an ecosystem's (or organism's) energy is inseparable from the ecosystem's (or organism's) growth.
In particular, energy is coupled with the fixation and release of CO2
Photosynthesis – Fixation of Carbon
Respirations – Release of Carbon
The "energy balance" is almost the same as "carbon balance" for biological systems.

10. TROPHIC STRUCTURE autotrophs = primary producers
organisms which produce organic material (OM) from inorganic chemicals and some source of energy
Heterotrophs = consumers = secondary producers:
organisms which require OM and energy from the biotic environment

11. Trophic Levels the order in which organisms receive solar energy
1st trophic level: autotrophs
2nd trophic level: herbivores
3rd trophic level: some carnivores
4th trophic level: other carnivores
5th…

12. Things aren’t that simple…
Many organisms fit in several levels.
Omnivores
hemiparasitic plants
Parasitic plants are on the second trophic level.
Where do insectivorous plants fit?

13. Making Connections
Food Chain: The passage of energy from a primary producer through a series of producers at higher trophic levels.
Plant - herbivore - carnivore, and so on
Food Web: a series of interconnecting food chains.