And so, just like isolucine, this Threatening contains a second CHYL carbon. And just like isolucine, this is the only nantomer of Threatening that is found in our proteins found inside our body. Now, notice that Serene is almost like Alanine, except one of the H atoms bound to this carbon is replaced with the hydroxyl group. And thyanine is almost like Vallene, except one of these methyl groups is replaced with a hydroxyl group. But because we have this electronegative atom, this is partially negative, this becomes partially positive. And so we have this dipole moment, and that makes this a relatively polar side chain and so a relatively polar amino acid.