BIO NMDCAT

Absolute specificity means the enzyme acts on only one specific substrate, unlike group specificity which acts on substrates with a common functional group.

DNA polymerase catalyzes the template-directed addition of deoxynucleotides to a growing DNA chain.

Isoenzymes are multiple forms of an enzyme that catalyze the same reaction but differ in kinetic properties, allowing for tissue-specific metabolic tailoring.

Many coenzymes are vitamin derivatives, such as pyridoxal phosphate (vitamin B6) which is required for aminotransferases.

Turnover number represents the maximum number of chemical conversions of substrate molecules per second that a single catalytic site executes.

Enzymes lower activation energy by providing an alternative reaction pathway where specific R-groups orient and stress substrates, stabilizing the transition state.

Substrate binding is mediated by multiple weak, non-covalent forces which are reversible, essential for both binding and product release.

A coenzyme is a non-protein organic molecule that binds transiently to an apoenzyme, allowing it to be separated by dialysis, unlike a prosthetic group.

The Induced Fit model states the active site is not rigid; substrate binding induces a conformational change that properly positions catalytic groups for optimized catalysis.

At high substrate concentrations, all enzyme active sites are occupied. The reaction velocity reaches a maximum (Vmax), and further substrate addition cannot increase the rate.

Km is a measure of an enzyme's affinity for its substrate, defined as the substrate concentration at which the reaction rate is one-half of the maximum velocity (Vmax).

Enzymes are biological catalysts that accelerate reactions by decreasing the activation energy. They do not provide energy, alter the equilibrium constant, or change the free energy change (ΔG) of the overall reaction.

The tertiary structure of an enzyme, which dictates the shape of the active site, is stabilized by hydrogen bonds, ionic interactions, hydrophobic interactions, van der Waals forces, and covalent disulfide bonds.

A prosthetic group is a non-protein unit that is covalently or very tightly bound to an apoenzyme, making it a permanent part of the functional holoenzyme.

The active site is a specific, flexible 3D pocket formed by a few amino acids that binds the substrate and catalyzes its conversion to product via weak interactions.

An enzyme accelerates both forward and reverse reactions equally by lowering activation energy without changing the equilibrium point or free energy.

Non-allosteric enzymes follow Michaelis-Menten kinetics, where the plot of V₀ vs. [S] is a rectangular hyperbola: first-order at low [S] and zero-order at high [S].

The triad allows histidine to act as a powerful general base catalyst, abstracting a proton from the serine hydroxyl group to make it a nucleophile.

Irreversible inhibitors covalently modify essential residues or cofactors, leading to permanent enzyme inactivation.