What kind of molecule typically becomes more reactive when phosphorylated?

Phosphorylation is a biochemical process where a phosphate group is added to a molecule, usually at the expense of ATP, and this modification can significantly alter the chemical properties and reactivity of the molecule. Specifically, when intermediates in metabolic pathways are phosphorylated, they often become more reactive due to the introduction of a negatively charged phosphate group.

The addition of the phosphate group can destabilize the molecule by introducing steric hindrance or by altering intramolecular interactions, thus making it more likely to participate in subsequent chemical reactions. This increased reactivity is crucial for metabolic processes, such as energy transfer and signal transduction, where phosphorylated intermediates play key roles in catalyzing reactions or transmitting signals within the cell.

In contrast, neutral molecules, hydrophobic molecules, and inorganic ions do not typically undergo the same significant increase in reactivity as a result of phosphorylation. Neutral molecules may not have the charge or structural changes that enhance reactivity, hydrophobic molecules often remain unreactive due to their lack of polarity and solubility in aqueous environments, and while inorganic ions may play important roles in cellular functions, they do not experience changes in reactivity through phosphorylation like organic intermediates do.