Enzymes Flashcards
do not alter the free energy (∆G) or enthalpy (∆H) change that accompanies the reaction nor the final equilibrium position; rather, they change the rate (kinetics) at which equilibrium is reached
enzymes
types of enzymes:
catalyze oxidation reduction reactions that involve the transfer of electrons
oxidoreductases
types of enzymes:
move a functional group from one molecule to another molecule
transferases
types of enzymes:
catalyze cleavage with the addition of water
hydrolases
types of enzymes:
catalyze cleavage without the addition of water and without the transfer of electrons
lyases
types of enzymes:
catalyze the interconversion of isomers, including both constitutional isomers and stereoisomers
isomerases
types of enzymes:
are responsible for joining two large biomolecules, often of the same type
ligases
indicates how tightly the enzyme-substrate complex (ES) binds
K(m)
K(m):
indicates tighter binding between [ES]
low value
K(m):
indicates looser binding between [ES]
high value
results when the inhibitor is similar to the substrate and binds at the active site; binds E, K(m) increases, V(max) stays the same; increases slope on a Lineweaver-Burke plot
competitive inhibition
results when the inhibitor binds only with the enzyme-substrate complex; binds ES, K(m) decrease (more ES formed), V(max) decreases; parallel line on Lineweaver-Burke plot
uncompetitive inhibition
results when the inhibitor binds with equal affinity to the enzyme and enzyme-substrate complex; binds E and ES, K(m) stays the same, V(max) decreases; increases slope on a Lineweaver-Burke plot
noncompetitive inhibition
