Systems

A System Is an organized collection of interdependent components that perform a function and which are connected through the transfer of energy and/or matter All the parts are linked together and affect each other.

A system has properties and functions NOT present in the individual components. The whole (system) is greater than the sum of the parts. Properties of the whole (system) CANNOT be predicted with the study of the parts on their own. This is called “Synergy”

Characteristics of Systems What are the characteristics? Component parts- reservoirs, storages, stocks, accumulations Processes-flows, transformations, transfers, reactions, photosynthesis, respiration. Positive Feedback- mechanism that moves a system to a new equilibrium. Ex- Heating of the ocean. Negative feedback- mechanism for maintaining equilibrium Ex- Thermostat

1. OPEN SYSTEM : a system in which both matter and energy are exchanged across boundaries of the system. Systems are defined by the source and ultimate destination of their matter and/or energy.

2. CLOSED SYSTEM : a system in which energy is exchanged across boundaries of the system, but matter is not.

3. ISOLATED SYSTEM : a system in which neither energy nor matter is exchanged across boundaries of the system. NO SUCH SYSTEM EXISTS!!! Most natural living systems are OPEN systems.

Two basic processes must occur in an ecosystem: 1.A cycling of chemical elements. 2.Flow of energy. TRANSFERS: normally flow through a system and involve a change in location. TRANSFORMATIONS: lead to an interaction within a system in the formation of a new end product, or involve a change of state.

Components of a system: 1.Inputs such as energy or matter. Calories Protein Human Body

2. Flows of energy within the systems at certain rates. Human Metabolism Calorie s Protein

3.Outputs of certain forms of matter or energy that move out of the system into sinks in the environment. Calories Protein Human Metabolism Waste Heat Waste Matter

4. Storage areas in which energy or matter can accumulate for various lengths of time before being released. Calorie s Protein Human Metabolism fat insulation muscle fiber hair, nails enzymes

Inputs and Outputs

Thermodynamics Is the study of the energy transformations that occur in a system. It is the study of the flow of energy through nature.

1 st Law of Thermodynamics States that energy can be transferred and transformed, but it CANNOT be created nor destroyed.

Thermal equilibrium = inputs equal outputs over a long period of time.

2 nd Law of Thermodynamics States that every transformation results in a reduction of the FREE ENERGY (useable energy). Energy transfers and transformations increase ENTROPY (disorder, randomness or chaos). Law of Entropy. Energy always tends to go from a more usable (higher quality) form to a less usable (lower quality) form.

Any conversion is less than 100% efficient and therefore some energy is lost or wasted. Usually this energy is lost in the form of HEAT (= random energy of molecular movement). We usually summarize it as respiration. Solar energy Waste heat Chemical energy (photosynthesis) Waste heat Waste heat Waste heat Chemical energy (food) Mechanical energy (moving, thinking, living)

Only 25% of chemical “E” stored in gasoline is transformed in to motion of the car and 75% is lost as heat!!

Heat ,000 10,000 Usable energy available at each tropic level (in kilocalories) Producers (phytoplankton) Primary consumers (zooplankton) Secondary consumers (perch) Tertiary consumers (human) Decomposers