Chapter 6 How Enzymes Work

hydrolysis

cleavage by water

increasing the temperature, increasing the concentrations of the reacting substances, and adding a catalyst

the three ways to increase the rate of a chemical reaction are…

enzymes

protein or RNA catalysts that increase the rates of chemical reactions in living systems

catalyst

a substance that participates in a chemical reaction yet emerges at the end in its original form

ribozymes

enzymes made of RNA

reaction specificity

the ability of an enzyme to discriminate between possible substrates and to catalyze a single type of chemical reaction

chymotrypsin

this digestive enzyme catalyzes the hydrolysis of the peptide bond following almost any large nonpolar residue such as Phe, Trp, or Tyr, and can also catalyze the hydrolysis of other amide bonds and ester bonds

oxidoreductases

these enzymes catalyze oxidation-reduction reactions

transferases

these enzymes catalyze the transfer of functional groups

hydrolases

these enzymes catalyze hydrolysis reactions

lyases

these enzymes catalyze group elimination to form double bonds

isomerases

these enzymes catalyze isomerization reactions

ligases

these enzymes catalyze bond formation coupled with ATP hydrolysis

isozymes

multiple enzymes that catlyze the same reaction — usually share a common evolutionary origin but differ in their catalytic properties

-ΔG

when the products have a lower free energy than the reactants and the reaction is said to be spontaneous