Fundamentals of Biochemistry - A. A. Anisimov 1986

Enzymes
General and Specific Properties of Enzymes

As catalysts — substances that accelerate reactions — Enzymes share A number of General Properties with chemical, non-biological catalysts.

1. Enzymes do not become part of the final reaction products and emerge from the reaction unchanged. They are not consumed in the course of catalysis.

2. Enzymes cannot initiate reactions that contradict the Laws of Thermodynamics; they only accelerate those reactions that can proceed even in their absence.

3. As a rule, enzymes do not shift the reaction equilibrium, but merely accelerate its attainment.

Enzymes are also characterized by specific properties that distinguish them from chemical catalysts, reflecting their biological nature.

1. In terms of chemical Structure, all enzyme molecules are Proteins.

2. The catalytic efficiency of enzymes is higher than that of non-biological catalysts (the reaction rate in the presence of an enzyme is several orders of magnitude higher than with chemical catalysts).

3. Enzymes exhibit high Specificity and selectivity of action toward substrates, i.e., the substances whose transformation they catalyze.

4. One of the MOST IMPORTANT PROPERTIES of enzymes as biocatalysts is their regulatability. The Regulation of the enzymatic machinery ensures the coordination of all metabolic processes in time and space, aimed at reproducing living matter, maintaining intracellular Homeostasis, and adapting to changing external conditions (see Sec. 12.5).

5. Unlike non-enzymatic reactions, enzymatic processes exhibit negligible Side Reactions, boasting an almost 100% product yield.