- Energy - Measuring energy - Laws of Thermodynamics - Photosynthesis
The universe is made up of matter and energy.
Energy is either kinetic or potential.
Kinetic energy is energy in motion. Potential energy is energy in storage. Energy can be changed from one form to another.
Energy is measured in calories.
1 calorie is the amount of heat required to raise the temperature of 1 gram of water 1 degree Celsius. This is a very small amount, so energy is usually measured in kilocalories.
There are two laws that govern thermodynamics or the change of energy from one form to another. The 1st law states that energy is neither created nor destroyed, but can be converted from one form to another.
The second law states that in any energy conversion, some of the usable energy is lost. Entropy is the measure of degree of disorder in a system, so increasing entropy means increasing disorder.
Producers (green plants) use light energy to make glucose from carbon dioxide and water. Consumers (living organisms) break down organic matter made by producers and consume them.
This same principle applies to ecosystems. During this process, some usable energy is lost and released to the universe, no longer available to ecosystems. Sunlight is necessary to resupply the energy production process.