Enzymes

Coenzyme

________: organic molecule that participates in reaction but is left unchanged afterward.

Cofactor

________: usually inorganic ion that temporarily binds to enzyme.

Enzyme side chains

________ act as proton donors and acceptors.

Substrate binding site

________ excludes H2O & lowers the dielectric constant strengthening electrostatic interaction between E and S.

Specificity

________ is controlled by the structure- the unique fit of substrate with enzyme controls the selectivity for substrate and the product yield.

Enzymes

________ also are generally specific for a particular steric configuration (optical isomer) of a substrate.

Substrate

________ fits the catalytic site with proper orientation to catalytic groups.

Active site

________: the region on the enzyme where the substrate binds.

Prosthetic groups

________: small molecules permanently attached to the enzyme.

enzymatic reaction

In a(n) ________, the substrate binds to the active site of the enzyme.

Alcohol dehydrogenase

________ always catalyzes oxidation- reduction reactions but attacks a number of different alcohols.

Enzyme changes

________ shape- tighter induced fit, bringing chemical groups in position to catalyze the reaction.

Enzymes

________ are highly specific for the kind of reaction they catalyze, but is not always true of substrates they attack.

Enzymes substrate

the reactant that an enzyme acts on

Active site

the region on the enzyme where the substrate binds

The specificity of an enzyme

fit between the active site and that of the substrate

Specificity is controlled by the structure

the unique fit of substrate with enzyme controls the selectivity for substrate and the product yield

Enzyme changes shape

tighter induced fit, bringing chemical groups in position to catalyze the reaction

Prosthetic groups

small molecules permanently attached to the enzyme

Cofactor

usually inorganic ion that temporarily binds to enzyme

Coenzyme

organic molecule that participates in reaction but is left unchanged afterward

Proximity and Strain Effects

Substrate fits the catalytic site with proper orientation to catalytic groups. 

Enzyme conformation changes to give a strained E-S complex.  

Facilitates attaining the transition state. 

Electrostatic Effects

Substrate binding site excludes H2O & lowers the dielectric constant strengthening electrostatic interaction between E and S.

Acid-Base Catalysis

Enzyme side chains act as proton donors and acceptors

Covalent Catalysis

Powerful nucleophilic side chain forms an unstable covalent bond to the substrate.