For 10 points, name this dicarboxylic acid that makes fruits like apples taste sour.
Pili in Mycobacterium tuberculosis use the enzyme that synthesizes this compound to bind to laminin. The export of this compound by SLAC1 in guard cells at high levels of carbon dioxide is required for stomatal closure. Glyoxylate condenses with acetyl Co-A to form this compound. This compound is not an amino acid, but it is transported from mesophyll cells to bundle sheath cells in C4 plants, since it can be formed by carboxylating, then reducing, PEP. It is antiported against alpha-ketoglutarate to shuttle electrons from glycolysis into the mitochondrion, a role it shares with aspartate. The addition of water to fumarate gives this compound. Its oxidation yields oxaloacetate in the final step of the citric acid cycle. For 10 points, name this dicarboxylic acid that makes fruits like apples taste sour.
Pili in Mycobacterium tuberculosis use the enzyme that synthesizes this compound to bind to laminin.
malate [or malic acid]