Metabolic pathways Flashcards
Metabolic pathways are controlled
by the presence or absence of particular enzymes
Rates of enzymatic reactions can be controlled
by intracellular and extracellular signal molecules
anabolic pathways require
energy and involve biosynthetic process
catabolic pathways release
energy and involve the breakdown of molecules
Most metabolic reactions are
reversible and the presence of substrate or removal of product will drive a sequence of reaction in particular direction
Metabolic pathways can have
irreversible steps and alternative routes.
The activity of enzymes depends
of their flexible and dynamic shape.
substrate molecules have
an affinity for the active site of an enzyme
The enzymes is flexible and the substrate
can induce the active site to change shape by induced fit.
The active site can
orientate the substrate molecules so they fit more closely
The energy required to initiate a chemical reaction is
called the activation energy
Enzymes lower
activation energy
Products of the enzyme
have a low affinity for the active site of the enzyme , and are released.
The concentration of substrate and end product affect the
direction and rate of enzyme energy
Enzyme often act in
in groups or as multi-enzyme complexes
Non-competitive inhibition
involves the binding of molecules that change the shape of the enzyme and its active site, so that it can no longer combine with substrate molecules
Competitive inhibition
involves competitive fort the active site of the enzyme form molecules that resemble the substrate
competitive inhibition can be reduced by
by increasing substrate concentration
Feedback inhibition is a method of
metabolic control in which the end product binds to an enzyme that catalyse a reaction early in the pathway
