Biosphere: (How Energy Enters The Biosphere) Flashcards
Study of ecology:
•1866 German-scientist Ernst Haekel invented term ecology.
•origin: Greek word —> house/home.
•ecology: the study of the relationships between living things (organisms) and their non-living surroundings, the environment.
•study of ecology may be large or small scale.
Divisions of the biosphere:
-biosphere: the narrow zone around the Earth that contains life.
Earths life system:
•system: object or group of objects that scientists study. The system may have distinct or arbitrary boundaries.
•TWO types of systems:
-open system: one that allows energy and matter to cross the systems boundary—to enter and leave it.
-closed system: one that allows only energy (but not matter) to cross the boundary.
Is Earth an open or closed system?
•in terms of matter, Earth is essentially a closed system.
-all the matter that is here, is here to stay.
-with the exception of meteorites and satellites etc.
•in terms of energy, the Earth is an open system
-suns energy enters, some energy is radiated back into space.
The need for energy:
•all organisms need energy to survive.
•energy on earth originates from the SUN.
•photosynthesis takes energy from the sun—> stores in high energy molecules (such as glucose).
•cellular respiration allows organisms to breakdown glucose and release energy that can be used to maintain life processes.
Life processes:
Growth, movement, repair, reproduction.
Albedo effect:
•albedo = the amount of reflected energy.
•light-coloured, reflective surfaces have higher albedo.
•dark-surfaces have lower albedo.
Fate of energy in the biosphere:
•matter cycles within the biosphere BUT energy passes through it and does not cycle.
•second law of thermodynamics: as energy is converted from one form to another, some energy is always lost in the form of heat (as no conversion is ever 100% efficient).
•this “lost” energy in the form of heat is NOT useable to any other living organisms (hence the name “lost”).
