The phrase "essential to the function" is correct and can be used in written English.
Example: Understanding basic grammar rules is essential to the function of writing effective sentences.
But highly ordered cellular architectures essential to the function of complicated organs like the heart are much harder to replicate.
It was hence concluded that despite its strict conservation and unique modification, the diphthamide histidine appears not to be essential to the function of human EF-2 in protein synthesis.
Protein substrate specificity is essential to the function of the enzyme and has been exploited to find enzyme-specific inhibitors for antitumor therapies.
In summary, stability, transient response, feedback and controllability are basic dynamic properties of the biological systems and are essential to the function of the cells and organisms.
Making the correct choice between transcription elongation and transcription termination is essential to the function of RNA polymerase II, and fundamental to gene expression.
It also appears unlikely that PrgI and the Bcl-2 protein family would evolve through a convergent process since the helix-turn-helix is such a simple and ancient motif [64] and essential to the function of both proteins.
But, unlike governesses, housemaids were essential to the functioning of most Victorian homes.
Accounting is essential to the functioning of the economy and, indeed, society in general.
Cooperation and reciprocity are essential to the functioning of both nature and society.
Rather, we are in the world of norms, precepts essential to the functioning of a constitutional democracy.
We have shown here that least attractive species that represent an 'overlooked diversity' are essential to the functioning of ecosystems.
