MCAT Biochemistry Ch. 2 Enzymes

Catalysts

1. Ligase
2. Lyase
3. Hydrolase
4. Oxidoreductase
5. Isomerase
   1. Transferase

Enzyme that catalyzes oxidation-reduction reactions that involve the transfer of electrons. The electron donor in these reactions is the reductant, & the acceptor is the oxidant. Enzymes called dehydrogenase or reductase are oxidoreductases.

Enzyme that catalyzes breaking of compound into 2 molecules using the addition of water. Some common hydrolases are phosphatase (cleaves phosphate groups from molecules), peptidase (breaks down protein), & nuclease (break down nucleic acids)

Enzymes that catalyze the cleavage of a single molecule into 2 products. They can also do the reverse of this & catalyze the synthesis of 2 molecules into a single molecule (in these cases they are called synthases). They are involved w/ synthesis of tiny molecules.

Enzyme that catalyzes the interconversion of isomers, both constitutional & stereoisomers.

Enzyme that moves a functional group from 1 molecule to another molecule. Kinases (which catalyze transfer of a phosphate group) are transferases.

A trasnferase enzyme that catalyzes the transfer of a phosphate group

Enzyme that catalyzes the joining of 2 large biomolecules (addition or synthesis reactions), often of the same type

Kinetics (speed)

Enzyme & substrate are exactly complementary

Enzyme & substrate undergo conformational changes to interact fully once the substrate starts to bind.

As the substrate concentration increases, the reaction rate does as well until a max value is reached

Temperature (increases enzyme activity until too hot & then can denature them), pH (most enzymes have specific pH they work best at), & salinity

1. Competitive Inhibition
2. Noncompetitive Inhibition
3. Mixed Inhibition
4. Uncompetitive Inhibition