The Science of Existence (70-1) Enzymes


Alcoholic fermentation is an act correlated with life. ~ Louis Pasteur

French chemist and microbiologist Louis Pasteur, thirsty for knowledge, concluded in 1857 that some vital force catalyzed yeast in its fermentation of sugar into alcohol. He termed that vitality ferments. What he discovered were enzymes in action. German physiologist Wilhelm Kühne coined the term enzyme in 1877.

An enzyme is able to speed up a chemical reaction by as much as 10 million times. It had to do this by lowering the energy of activation – the energy of forming the activated complex. It could do this by forming strong bonds with the activated complex, but only weak bonds with the reactants or products. ~ Linus Pauling

An enzyme is commonly defined as a protein that acts as a catalyst in reactions involving proteins or other substrates, typically polymers. A polymer is a large molecule (macromolecule) comprising repeating molecular units (monomers).

Enzymatic action is the karmic wheel of organic life in polymeric construction (anabolism) and deconstruction (catabolism). Enzymes enable the manufacture of macromolecules which may be consumed. Conversely, consumption requires enzymes to break big molecules down to release the energy within.

Because proteins are picky about being prodded to perform, every biochemical reaction is promoted by a specific enzyme.

Every organism contains a vast number of different enzymes, involved in a complex web of metabolic interactions. ~ Andrew Clarke

Enzymes are often quite specific in their binding, but some are also produced to be non-specific, with specificity generated by controlling access to specific substrates – a learning mechanism. Proteins can thus be made to act like switches, by having 2 or more conformations, thus able to interact differently with signaling proteins. This is a facet of intracellular communication.

An enzyme can use a rare and transient conformational state in its substrate to direct an outcome. ~ Canadian geneticist David Pulleyblank

Enzymes dance to do their job. Subtle changes in shape play a crucial role in enzyme function. Enzyme conformational changes are highly dynamic.

2 enzymes with virtually identical molecular shapes may catalyze reactions at very different rates. One may regulate insulin production in humans, while its evil twin gives a bacterium the power of bubonic plague.

The rate of molecular motions is critical to enzyme function. Context matters.

The enzyme responsible for insulin regulation moves slowly, ensuring certainty in cellular processing. Conversely, the plague enzyme is carefree; moving 30 times faster. While proper construction requires meticulousity, the power for destruction can be swiftly rendered.

The exuberance of enzymes often needs to be adjusted to suit cellular needs. The rate of enzymatic activity is affected by a variety of conditions: temperature; ambient chemical environ, such as pH; and chemical concentrations. Whereas activators increase activity rate, inhibitors slow enzymes down. Many drugs and poisons are enzyme inhibitors.