Tyrosine, an amino acid with a hydroxyl group, forms hydrogen bonds due to its ability to donate and accept protons. The pH of a solution influences the protonation state of tyrosine, affecting its interactions with other molecules. When the pH is below its isoelectric point (pI), tyrosine is positively charged and forms hydrogen bonds with negatively charged molecules. Conversely, when the pH is above its pI, tyrosine becomes negatively charged and forms hydrogen bonds with positively charged molecules. These pH-dependent interactions play a crucial role in protein structure and function, as well as in interactions with DNA and other polar molecules.
