https://pages.htgaa.org/2026b/gracious-isoah/week-03-cfps/index.htmlA. COMPARE CELL-FREE REACTION COMPOSITIONS Why does the concentration of potassium glutamate and magnesium glutamate differ between compositions? Which is more sensitive? Potassium glutamate and magnesium glutamate are water-soluble ionic salts added to the buffer of cell-free protein synthesis to mimic the cytoplasmic environment of the cell. They provide critical ions like Mg²⁺ and K⁺ at concentrations required for transcription, translation, ribosome function, and energy metabolism. Glutamate is generally a more physiologically suitable counter-anion than chloride for many bacterial CFPS systems. CFPS yields are known to be more sensitive to magnesium glutamate. It provides a more constrained variable, Mg²⁺. In a study by Cai et al., changes of about 1-2 mM in concentration can increase/decrease protein yield. Free Mg²⁺ is a core component of the translation machinery. It stabilizes rRNA and the functional structure of RNA. Other CFPS reagents, including ATP, GTP, and nucleic acids, bind to Mg²⁺ due to its chelating effect.Hugoen