All living cells need pH buffers because most cellular processes only work properly in a very narrow pH range, and buffers prevent sudden, harmful changes in pH.

Key idea in one sentence

The best explanation is: cells need pH buffers to maintain a stable internal pH so that enzymes, proteins, and metabolic reactions are not damaged or disrupted by small additions of acids or bases.

Slightly longer explanation

  • Enzymes (the proteins that drive almost every reaction in a cell) have an optimal pH; if pH shifts, their shape and activity change or they denature, so reactions slow or stop.
  • Normal cell activity constantly produces acids and bases; without buffers, these by‑products would quickly change pH to lethal levels.
  • Buffers are usually weak acids and their conjugate bases that “soak up” added H⁺ or OH⁻, so the pH stays nearly constant (homeostasis).

So, if this was a multiple‑choice question, you’d pick the answer that says something like:

“Because buffers help maintain a constant internal pH, protecting enzymes and other cell components from being harmed by small changes in acidity or basicity.”

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