Example: ALCOHOL DEHYDROGENASE

(reaction type): Oxidation with NAD+

Type of reaction catalyzed: Transfer of electrons

another ex. Lactate dehydrogenase

Class 2

Ex: Hexokinase

(reaction type): Phosphyorylation

Catalyze transfer of C-, N-, or P-containg Groups

Ex: Carboxypeptidase A

(rxn type): Peptide Bond Cleavage

Catalyze cleavage of bonds by addition of water

Ex: Pyruvate Decarboxylase

(rxn type): Decarboxylation

Catalyze cleavage of C-C, C-S, or C-N bonds

Ex: Maleate Isomerase

(rxn type): cis-trans isomerization

catalyze racemization of optical or geometric isomers; transfer of groups within molecules to yield isomeric forms

Ex: Pyruvate Carboxylase

(rxn type): Carboxylation

Catalyze formation of bonds between carbon and O, S, N couples to hydrolysis of high-energy phosphates (ATP cleavage)

[Substrate]

pH (eg. Trypsin)

Temperature (denaturation)

Inhibitor binds with free enzyme at the active site where [S] would normally bind; so CI competes for the same site to form an EI complex.

E + I <---> EI

*Km changes -- the amount of [substrate] increases to get 1/2Vmax.

*Vmax stays the same -- @Vmax, so much [S], I can't bind

Ex. Statin Drugs or Methotrexate

Inhibitor can bind with Enzyme and Enzyme-Substrate complex; so it's not reversed by increasing [S]

E+I <---> EI

ES + I <---> ESI

*Km stays the same

*Vmax changes -- it is reduced

because no matter how high [S] gets, I can still bind to E, since it binds to a diff site than S binds to

Number of enzyme units per mg protein

unit/mg protein

--measures enzyme purity

1) BIND THE SUBSTRATE (relates to Km)

--decrease (small) Km, better E+S binding

b/c of a high affinity of enzyme for substrate, b/c a low concentration of substrate is needed to half-saturate the enzyme -- to reach a velocity that is 1/2Vmax.

2) CATALYZE THE REACTION (relates to Vmax)

BINDING ENERGY

COVALENT CATALYSIS

ACID-BASE CATALYIS

METAL ION CATALYSIS