Enzymes, Catalysis, and Serine Proteases

Vocabulary flashcards from lecture notes on enzymes, catalysis, and serine proteases.

Serine Proteases

Enzymes that hydrolyze peptide bonds.

Covalent Catalysis

Catalysis involving the formation of temporary covalent bonds between the enzyme and the substrate.

Transition State

A high-energy, unstable state during a chemical reaction that enzymes help to lower.

Deprotonated Lysine Side Chain

The deprotonated form of lysine, acting as a nucleophile.

Imine/Schiff Base

Chemical species with a carbon-nitrogen double bond, important in biochemistry and metabolism.

Acid-Base Catalysis

Catalysis that relies on the acidic or basic properties of amino acid side chains.

Metal Ion Catalysis

Catalysis involving metal ions to stabilize intermediates or facilitate reactions.

Carbonic Anhydrase

An enzyme in the circulatory system that catalyzes the reaction of CO2 and water to form bicarbonate and a proton.

Catalytic Triad

A group of three amino acids (aspartate, histidine, and serine) that work together at the active site of some enzymes to facilitate catalysis.

Proximity and Orientation Effects

Non-adjacent amino acids brought together by protein folding that create a specific chemical environment within the active site of an enzyme

Selectivity Pocket

A pocket on the enzyme that dictates what substrate will bind

Chymotrypsin

Enzymes that cleave amide bonds C-terminal to large, aromatic, non-polar residues (phenylalanine, tryptophan, tyrosine).

Trypsin

Enzymes that cleave amide bonds C-terminal to positively charged residues (lysine and arginine).

Elastase

Enzymes that cleave amide bonds C-terminal to small hydrophobic residues (alanine).

Scissile bond

The specific amide bond that will be cleaved when a substrate binds an enzyme

N to C Terminus

The concept that proteins are synthesized from the N-terminus to the C-terminus

Convergent Evolution

A type of chemical evolution that occurs when dissimilar species independently evolve similar traits

Strong Hydrogen Bond

A bonding arrangement that allows a Histidine to become deprotonated through shared protonation

Transition State Stabilization

Electrostatic stabilization of the transition state within the oxyanion hole of serine proteases