Chapter 7 Vocab Flashcards
(93 cards)
What do cells do with energy?
convert it from one form to another
what is radiant energy?
the ultimate source of energy (photosynthesis; sun’s energy –> chemical energy)
what is matter?
anything at has mass and takes up space
what is energy?
the capacity to do work (change in state or motion of matter)
how much energy do photosynthetic organisms capture?
about 0.02%
how is energy expressed in units of work?
kilojoules, kJ
how is energy expressed in units of heat energy?
kilocalories, kcal
what does 1 kcal equal?
4.184kJ
what is thermodynamics?
heat and temperature and its relation to energy and work
mass is technically energy, what is the equation?
E=mc^2
what is potential energy?
the capacity to do work as a result of position or state (water behind a dam)
what is kinetic energy?
energy of motions is used, work is performed (water falling through a turbine)
what is an energy transformation?
occurs in series, kinetic energy is converted to potential energy or potential energy to kinetic
what is chemical energy?
potential energy stored in chemical bonds (food –>mechanical energy for muscles)
what does thermodynamics govern?
all activities of the universe
biological systems are?
open systems that exchange energy with their surroundings
what type of system is the universe?
closed
what is the first law of thermodynamics?
energy cannot be created or destroyed, only transferred or converted
-energy is the system plus sits surrounding
how do organisms obey the first law of thermodynamics?
by capturing energy from the environment and transforming it to a form that can be used for biological systems
according to the first law of thermodynamics, what happens to mass-energy of an object?
mass-energy does not change, it can only go from one form to another
what is the second law of thermodynamics?
during energy transformations, usable energy/energy available to do work is converted into heat and given off
what is heat
the kinetic energy of randomly moving particles or less- usable energy “disorganized energy”
what happens to usable energy according the second law of thermodynamics?
as heat is loss, the amount of usable energy available decreases over time
what is entropy?
the measure of the disorder or randomness of energy, organized and disorganized (Unusable energy in a system)