In the cytoplasm of practically all living cells, potassium is the major cation while sodium dominates in the media (seawater, extracellular fluids). Both prokaryotes and eukaryotes have elaborate mechanisms and spend significant energy to maintain this asymmetric K⁺/Na⁺ distribution. This essay proposes an original line of evidence to explain how bacteria selected potassium at the very beginning of the evolutionary process and why it remains essential for eukaryotes.

中文翻译：

---

钾如何成为主要的生物阳离子：自生命开始以来的代谢、化学渗透和阳离子选择性

在几乎所有活细胞的细胞质中，钾是主要的阳离子，而钠在介质（海水、细胞外液）中占主导地位。原核生物和真核生物都有复杂的机制并花费大量能量来维持这种不对称的 K ⁺ /Na ⁺分布。这篇文章提出了一个原始证据来解释细菌如何在进化过程的一开始选择钾，以及为什么它对真核生物仍然必不可少。