Chapter 8 VOCAB*** Flashcards
catabolic pathways
metabolic pathways release energy by breaking down complex molecules to simpler compounds…breakdown pathways
anabolic pathways
consume energy to build complicated molecules from simpler ones; they are sometimes called biosynthetic pathways
bioenergetics
the study of how energy flows through living organisms
energy
the capacity to cause change
kinetic energy
energy associated with the relative motion of objects
heat/ thermal energy
kinetic energy associated with the random movement of atoms or molecules
Potential energy
energy that matter possesses because of its location or structure
chemical energy
the potential energy available for release in a chemical reaction
thermodynamics
study of energy transformations that occur in a collection of matter
First law of thermodynamics
energy of the universe is constant; energy can be transferred and transformed, but it cannot be created or destroyed….also known as principle of conservation of energy
entropy
a measure of disorder, or randomness…the more randomly arranged a collection of matter is, the greater the entropy
second law of thermodynamics
every energy transfer or transformation increases the entropy of the universe…although order can increase locally, there is an unstoppable trend toward randomization of the universe as a whole
spontaneous process
a process that can occur without an input or energy
free energy
the energy that may be extracted from a system at constant temperature and pressure
exergonic reaction
a net release of free energy
spontaneous
it is energetically favorable not that it will occur rapidly
endergonic reaction
one that absorbs free energy from its surroundings
energy coupling
the use of an exergonic process to drive an endergonic one
enzyme
a macromolecule that acts as a catalyst
catalyst
chemical agent that speeds up a reaction without being consumed by the reaction
activation energy
initial investment of energy for starting a reaction-the energy required to contort the reactant molecules so the bonds can break- is known as the free energy of activation or activation energy
substrate
the reactant an enzyme acts on
enzyme substrate complex
this is formed when the enzyme binds to its substrate
active site
typically a pocket or groove on the surface of the enzyme where catalysis occurs
induced fit
brings chemical groups of the active site into positions that enhance their ability to catalyze the chemical reaction
cofactors
the non protein helpers for catalystic activity
coenzyme
if the cofactor is an organic molecule, it is more specifically called a coenzyme
competitive inhibitors
reduce the productivity of enzymes by blocking substrates from entering active sites
noncompetitive inhibitors
do not directly compete with the substrate to bind to the enzyme at the active site…instead they impede enzymatic reactions by binding to another part of the enzyme
allosteric regulation
the term used to describe any case in which a protein’s function at one site is affected by the binding of a regulatory molecule to a separate site
cooperativity
this mechanism amplifies the response of enzymes to substrates..one substrate molecule primes an enzyme to act on additional substrate molecules more readily
feedback inhibition
metabolic pathway is switched off by the inhibitory binding of its end product to an enzyme that acts early in the pathway
metabolism
the totality of an organism’s chemical reactions
metabolic pathway
begins with a specific molecule, which is then altered in a series of defined steps, resulting in a certain product
