At the pH of most bodily fluids which functional group will lose a proton and which functional group will accept a proton?

At the pH of most bodily fluids (around 7.4), carboxylic acid functional groups (-COOH) typically lose a proton, becoming negatively charged carboxylate ions (-COO⁻). Conversely, amino functional groups (-NH₂) tend to accept a proton, becoming positively charged ammonium ions (-NH₃⁺). This proton transfer is crucial for maintaining the acid-base balance in biological systems.