ch 3 vocab Flashcards
enzyme
an organic molecule,
typically a protein, that catalyses
(speeds up) specific reactions
catalyst
a substance capable
of increasing the rate of a reaction
without being used up
catalyse
to increase the rate
of a reaction
substrate
the reactant of a
reaction catalysed by an enzyme
reactant
a molecule that
undergoes a transformation into
a product. When enzymes are
involved, the reactant is called
a substrate
product
the transformed molecule
created in a reaction
active site
the part of an
enzyme where the substrate binds
enzyme-substrate complex
the structure formed when an
enzyme and substrate are bound
together
conformational change
a change
in the three-dimensional shape of
macromolecules such as proteins
activation energy
the energy
required to initiate a reaction
collision theory
explanation of
chemical reactions that states that
in order to react molecules must
hit one another
denature
the disruption of
a molecule’s structure by an
external factor such as heat
biochemical pathway
a series
of enzyme-catalysed biochemical
reactions in which the product
of one reaction becomes the
substrate of the next reaction. Also
known as a metabolic pathway
optimal
the point at which for a
given condition (e.g. temperature),
the maximum function of an
enzyme occurs. Also known
as optimum
conformational change
a change
in the three-dimensional shape of
macromolecules such as proteins
saturation point
the point
at which a substance (e.g. an
enzyme) cannot receive more
of another substance (e.g.
a substrate)
limiting factor
a factor that
prevents the rate of reaction from
increasing
limiting reagent
a reactant that
prevents the rate of reaction from
increasing
enzyme inhibitor
a molecule that
binds to and prevents an enzyme
from functioning
competitive inhibition
the hindrance of an enzyme
by blocking the active site and
preventing the substrate
from binding
allosteric site
a region on an
enzyme that is not the active site
non-competitive inhibition
the hindrance of an enzyme by
binding to an allosteric site and
changing the shape of the active
site to prevent the substrate from
binding
reversible inhibition
enzyme inhibition that involves
weaker bonds that can be
overcome
irreversible inhibition
enzyme inhibition that involves
stronger bonds that cannot be
broken
