1. Write complete names for each of the following compounds, including designation of stereochemistry:

2. All of the naturally occuring amino acids are called L because they have a stereochemistry that was historically correlated with one stereoisomer of glyceraldehyde, shown below.

L-Glyceraldehyde and the natural amino acids all have the S absolute configuration. The two exceptions are glycine and cysteine. Look up their 3-dimensional structures and explain why they are different.