11-Lecture_11_3

Enzymes

Proteins that act as catalysts to increase reaction rates without being consumed.

Active Site

A specific region in an enzyme where the substrate binds.

Transition State (TS)

The highest energy state during a reaction, where bonds are being broken and formed.

Catalysis

The process of increasing the rate of a chemical reaction by a catalyst.

Oxidoreductases

Enzymes that catalyze oxidation-reduction reactions, transferring electrons.

Transferases

Enzymes that catalyze the transfer of functional groups from one substrate to another.

Hydrolases

Enzymes that catalyze the cleavage of bonds by the addition of water.

Lyases

Enzymes that catalyze the addition or removal of groups to form double bonds.

Isomerases

Enzymes that catalyze the rearrangement of atoms within a molecule.

Ligases

Enzymes that facilitate the joining of two substrates with the use of ATP.

Acid-Base Catalysis

A catalytic mechanism where protons are transferred to stabilize transition states.

Covalent Catalysis

A catalytic mechanism involving temporary covalent bonds between the enzyme and substrate.

Metal Ion Catalysis

A form of catalysis where metal ions facilitate the reaction by stabilizing negative charges.

Enzyme Specificity

The ability of an enzyme to preferentially bind its substrate over other molecules.

Zymogens

Inactive enzyme precursors that require activation to function.

Proteolytic Activation

The process of converting inactive zymogens into active enzymes through cleavage.

Nucleophile

A chemical species that donates an electron pair to form a chemical bond.

Substrate Cleavage

The breaking of bonds in the substrate to convert it into products.

Chymotrypsin

A serine protease that cleaves peptide bonds in proteins, using a specific catalytic triad.

Peptide Bond

The covalent bond formed between amino acids in a protein.

Acyl-Enzyme Intermediate

A transient form that occurs during the enzymatic reaction where the enzyme is covalently bonded to the substrate.

Hydrophobic Pocket

A region in the enzyme that assists substrate binding through hydrophobic interactions.

Oxyanion Hole

A region in the active site of an enzyme that stabilizes the transition state by accommodating a negatively charged intermediate.