For instance, many enzymes require sodium binding to ensure proper function.

This enzyme requires either ammonia or glutamine as the amino group donor.

These enzymes do not require any reduction system for catalysis.

The converting enzyme in these women required high levels of folic acid to function normally.

The enzyme requires the 5-deazaflavin structure, as well as an 8-hydroxy group in the substrate.

This membrane-bound enzyme is located in the plastids and requires Mg for activity.

More than five enzymes are thus required to synthesize these pigments, each working in concert.

In general, an ultrasensitive enzyme requires less than 81-fold increase in stimulus to drive it from 10% to 90% activity.

The first tungsten-requiring enzyme to be discovered also requires selenium (though the precise form is unknown).

This enzyme requires Mn, which cannot be replaced by Mg.