The structure of amino acid exists in the following two forms: The above structure is an example of…

The structure of amino acid exists in the following two forms: $\begin{matrix} \text{O} \\ || \\ \text{R}-\text{CH}-\text{C}-\text{OH} \\ | \\ \text{NH}_2 \end{matrix} \quad \xrightleftharpoons{\text{aqueous}} \quad \begin{matrix} \text{O} \\ || \\ \text{R}-\text{CH}-\text{C}-\text{O}^- \\ | \\ ^+\text{NH}_3 \end{matrix}$ The above structure is an example of ____. If the side chain $\text{R}$ is replaced by hydrogen, the amino acid is known as ____.