Topic 9 - Energy Transformations Flashcards
How do animals obtain energy?
Through converting potential (chemical) energy of C-H bonds into ATP (cellular respiration)
How do plants obtain energy?
Through converting sunlight into ATP directly and storing energy through C-H bonds via photosynthesis, which they then convert back into ATP
Anabolism
Pathways that require an energy input to synthesize complex molecules from simpler ones
Catabolism
Pathways in which complex molecules are broken down into simpler ones, releasing energy
Energy
The ability to do work
Kinetic energy
Energy of particles/objects in motion
Potential energy
Stored energy; the potential to do work
Chemical energy
Potential energy in chemical bonds that releases when these bonds are broken; transferred between molecules by electrons
Gibbs free energy
The usable energy, or energy that is available to do work; more specifically, the energy that takes place within a chemical reaction that is available after we account for entropy
- represented as ΔG
Exergonic reaction
A loss of free energy from reactants to products; spontaneous (ΔG < 0)
- Ex. catabolic reactions such as cellular respiration
Endergonic reaction
A gain of free energy from reactants to products; nonspontaneous (ΔG > 0)
- Ex. anabolic reaction such as photosynthesis
First Law of Thermodynamics
Energy is neither created nor destroyed; it is only converted from one form to another (e.g. potential energy to heat energy)
Second Law of Thermodynamics
Energy conversions are not completely efficient. Not all energy that is available to do work makes it through the conversion. Some energy is lost as heat and therefore increases entropy (disorder) in the universe
As an electron moves farther from the atomic nucleus, does it have more or less potential energy?
More
Define redox reactions and explain what happens in them.
Coupled reactions that involve the transfer of electrons from one chemical species to another
“OIL RIG”
Oxidation is loss of e-
Reduction is gain of e-
