Catalyst
speeds up chemical reactions
Enzymes
perform their functions repeatedly per protein
Exergonic Reactions
spontaneous reactions that can happen on their own and don’t need added energy
-releases more energy than invested in breaking the old bonds
Activation Energy (EA)
initial energy needed to break the bonds of the reactants
-molecules become unstable when enough energy is absorbed to break bonds
Energy Barrier
by reaching the transition state the reaction overcomes an activation energy barrier
Substrate
the reactant that an enzyme acts on
Enzyme-complex substrate
enzyme binds to its substrate
Active site
is the region of the enzyme often a pocket or groove that binds to substrate
Product
catalytic activity of enzyme converts substrate
Complementary fit
between the shape of the active site and the shape of a substrate is responsible for enzyme specificity
Induced fit
where the substrate binding site is flexible and can change shape to enhance binding
Saturated
all enzyme molecules have their active sites engaged
Denature
enzymes begin to denature at non-optimal temperatures
Extremophiles
the optimal temperature of an enzyme in an environment is dependent in which it typically function
pH
enzymes are less active and can denature at pH is different than their optimal pH
Cofactors
are enzyme helper molecules that bind to an enzyme permanently or reversibly
-essential for their partner enzyme to be active
Inorganic Cofactors
-Zinc
-Iron
-Copper
Organic Cofactors
called coenzymes
-Ex. Vitamin B12
Inhibitors
can selectively inhibit the action of specific enzymes
Irreversible inhibition
the enzyme can never function again after the inhibitor group
Reversible inhibition
bind to the enzyme by weak interactions
Metabolism
the totality of an organism’s chemical reaction
Metabolic pathway
a specific molecule is altered in a series to produce a product
Catabolic reactions
Releases energy by breaking it down
