Systems And Models Flashcards
Systems consist of… (4 things)
Storage (matter/energy), flows (inputs/outputs), processes (transfer/transformation) & feedback mechanisms (negative/positive).
Define a system
An assemblage of parts and the relationship between them, which together constitute an entity or whole.
Respiration (word equation)
Biomass -> carbon dioxide + water
Photosynthesis (word equation)
Carbon dioxide + water + light -> biomass + oxygen
Diffusion (word equation)
Nutrients + water -> (into) tree
Consumption (word equation)
Tissue (biomass) from 1 trophic level -> another trophic level
Open system
BOTH matter AND energy are exchanged across boundaries of the system.
Example of open system
People
Closed system
ENERGY NOT matter is exchange across boundaries of the system.
Examples of closed system
Atoms/molecules, the Earth, water/nitrogen cycle.
Isolated system
NEITHER energy NOR matter is exchanged across the boundary of the system.
Example of isolated system
DONT EXIST NATURALLY/ universe.
First law of thermodynamics
Energy cannot be CREATED or DESTROYED, only TRANSFORMED from one form to another. There is a FIXED AMOUNT OF ENERGY in the universe. Therefore living organisms must get their required energy from their environment and surroundings.
Second law of thermodynamics
When energy is CONVERTED from one form to another, some of the energy is DEGRADED into LESS-USABLE HEAT which disperses into the environment. Thus, the AMOUNT of energy remains the SAME, but it’s USABILITY DECREASES.
Steady-state equilibrium
A condition of an open system in which there are no changes over the long term, but in which there may be fluctuations of matter and energy, but the system as a whole remains more or less in a constant state.
