Final answer:
If an individual is missing a specific amino acid due to a poor diet, it would affect the ability of the cell to synthesize particular proteins, including those in neurons.
Step-by-step explanation:
The individual's neurons would not be able to synthesize proteins. Free amino acids available for protein construction are said to reside in the amino acid pool within cells. Structures within cells use these amino acids when assembling proteins. If a particular essential amino acid is not available in sufficient quantities in the amino acid pool, however, synthesis of proteins containing it can slow or even cease.