energy and energy transformations Flashcards
(16 cards)
law of thermodynamics
-apply to all matter and all energy transformations in the universe
-help us understand how cells harvest and transform energy to sustain life
energy
the capacity to do work
potential energy
energy stored as chemical bonds, concentration gradient
kinetic energy
the energy of movement
metabolism
-sum total of all chemical reactions occurring in a biological system at a given time
-involve energy changes
anabolic reactions
complex molecules are made from simpler molecules; energy is required
catabolic reactions
complex molecules are broken down to simpler ones; energy is released
law of thermodynamics rules
1) energy is not created nor destroyed in a closed system but can be transformed
2) when energy is converted from one to another, some of that energy becomes unavailable to do work
entropy (s)
-a measure of the disorder in a system
-unusable energy
enthalpy (h)
total energy
free energy (g)
usable energy that can do work
enthalpy-total energy (h) =
H= G + TS
total energy=free energy + (absolute temperature) (unusable energy)
change in free energy of a chemical reaction
^G=^H - T^S
change in free energy= total energy - (absolute temperature) (unusable energy)
if ^G is -: free energy is released
if ^G is+: free energy is required
exergonic
reactions release free energy(-^G)
-catabolism-complexity decreases (generates disorder)
endergonic
reactions consume free energy (+^G)
-anabolism-complexity (order) increase
ATP
(adenosine triphosphate)
-captures and transfers free energy
-ATP can be hydrolyzed to ADP and Pi, releasing a lot of energy for endergonic reactions
-can phosphorylate (donate a phosphate group to) other molecules, which gain some energy
