Enzymes - Part 1 Flashcards

Flashcards covering the basics of enzymes, their function, nomenclature, and industrial applications based on lecture notes.

Enzyme

Proteins that act as biological catalysts by accelerating chemical reactions.

Substrates

The molecules upon which enzymes act.

Allostery

The ability of a protein to change shape, resulting in a change in binding affinity at a different binding site.

Allosteric enzymes

Enzymes with the active site, as well as an additional site (allosteric site).

Activation energy

The energy barrier separating the reactants and the products in a chemical reaction.

Recommended enzyme name

Short name, most used, has the suffix ‘-ase’ attached to the substrate of the reaction or the description of the reaction performed.

Systematic enzyme name

More complete, complex enzyme name used when an enzyme must be identified without ambiguity.

Oxidoreductases

Catalyze reactions in which one molecule is oxidized while the other is reduced (transfer of electrons and hydrogens).

Transferases

Transfer carbon, nitrogen, or phosphate groups.

Hydrolases

Enzymes that catalyze a hydrolytic cleavage reaction (use water to break a chemical bond).

Lyases

Catalyze the cleavage of C-C, C-S, and C-N bonds (catalyzes the breaking of various chemical bonds by means other than hydrolysis and oxidation, often forming a new double bond or a new ring structure).

Isomerases

Catalyze the rearrangement of bonds within a single molecule, transfer of groups within molecules to yield isomeric forms.

Ligases

Join two molecules in an energy-dependent process; catalyze formation of bonds between carbon and O, S, and N coupled to hydrolysis of high energy phosphates.

Synthetase

Requires ATP (ligase class).

Synthase

No ATP required (lyase class).

Phosphatase

Remove phosphates (hydrolase class).

Phosphorylase

Transfer (add) inorganic phosphates (transferase class).

Active sites

Contain a special pocket with high specificity, containing amino acid side chains that participate in substrate binding and catalysis.