6. Does every amino acid have
a central carbon? To which
organic group is that central
carbon bound?

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
A group –COOH, an amine
group – NH2, an atom of –H
and a variable radical necessarily are
bound to the central of an amino
acid.