Question

many vitamins are essential to human health because they are precursors for coenzymes. many are also compounds that human cells cannot synthesize themselves and so must be obtained through diet. what would happen if a person could not obtain one of these vitamins from a food source?
an enzyme would lose its substrate specificity, causing it to catalyze many extra reactions that normally do not occur in a cell.
an enzyme would lack a critical chemical component required as a participant in the enzymes metabolic reaction.
an enzyme would not fold properly, making it unable to catalyze a vital metabolic reaction.
an enzyme would lack a metal ion at its active site that enables the enzyme to carry out its catalytic mechanism.
an enzyme would lose its ability to bind substrates, making it unable to catalyze an essential chemical reaction.

Explanation:

Vitamins are precursors for coenzymes which are crucial for enzyme - catalyzed metabolic reactions. Without a necessary vitamin (coenzyme precursor), an enzyme would lack a critical chemical component needed for its metabolic reaction.

Answer:

An enzyme would lack a critical chemical component required as a participant in the enzyme's metabolic reaction.