Chapter 8 Flashcards
metabolic pathway
a series of chemical reactions that either builds a complex molecule (anabolic pathway) or breaks down a complex molecule to simpler molecules (catholic pathway)
catabolic pathway
a metabolic pathway that releases energy by breaking down complex molecules to simpler molecules
anabolic pathway
a metabolic pathway that consumes energy to synthesize a complex molecule from a simpler molecule
bioenergetics
the study of how energy flows through living organisms
thermodynamics
the study of the energy transformations that occur in a collection of matter
first law of thermodynamics
energy of the universe is constant; it can be transferred and transformed, but it cannot be created or destroyed
entropy
a measure of molecular disorder or randomness
second law of thermodynamics
every energy transfer or transformation increases the entropy of the universe
spontaneous process
a process that leads to an increase in entropy and can proceed without requiring an input of energy
free energy
the portion of a system’s energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell
change in free energy equation
deltaG=deltaH-TdeltaS
change in free energy=change in enthalpy - temperature x change in entropy
exergonic reaction
net release of free energy
endergonic reaction
absorbs free energy from its surroundings
energy coupling
in cellular metabolism, the use of energy released from an exergonic reaction to drive an endergonic reaction
ATP
contains the sugar ribose, with the nitrogenous base adenine and a chain of three phosphate groups (the triphosphate group) bonded to it