The most commonly used diagnostic tool for tuberculosis is a simple skin test, though blood tests are becoming more commonplace. A small amount of a substance called PPD tuberculin is injected just below the skin of your inside forearm. You should feel only a slight needle prick.
The structure has a double bond and an adjacent atom with a lone pair, so it could have resonance. The possible resonance structures are below. The first structure has the most common bonding pattern for all of its atoms, so it is a reasonable Lewis structure.
Tertiary Structure: The Overall 3-Dimensional Shape of a Protein. A protein needs to adopt a final and stable 3-dimensional shape in order to function properly. The Tertiary Structure of a protein is the arrangement of the secondary structures into this final 3-dimensional shape. The sequence of amino acids in a protein (the primary structure) will determine where alpha helices and beta sheets (the secondary structures) will occure.